# Addzest DRX9255 Tuner



## --Kei-- (Sep 8, 2011)

Got one of these coming to replace my antique Alpine 7915M. Has anybody successfully modified the tuner to receive worldwide FM frequencies?
I found this guide for a McIntosh unit which should be made by clarion so in principal it should be similar. Finding a clarion unit to swap the tuners over is next to impossible in the UK as they are very rare and i'm not going to use a band expander as it degrades the quality too much.

I found some similar info to the above on some russian sites that suggest losing 1-1.5 turns from the coil would alter the band range to approximately the right point.

This is the 9255 tuner.









Apparently its the same mod on an HX-D1.


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## estione (Jul 24, 2009)

How much SQ are you expecting from radio 2 in wales lol


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## --Kei-- (Sep 8, 2011)

I only live on the border so presently my alpine picks up radio 2 perfectly, and i reckon the addzest would too. (but that would be all it picks up as its limited to 90MHz) Only reason i want to convert the tuner is because i'm a bit OCD about such things and i'd like it if i was able to use the radio to pick up local stations to check on traffic reports. (which I'll admit doesn't require supreme SQ)


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## estione (Jul 24, 2009)

Yea i was only joking, if you contact Yuri ( either on here or TA ) he might be able to help ( i belive he is a bit of a guru on these, Other than that i'm afraid i cant really help sorry


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## RattyMcClelland (Nov 28, 2008)

Try Gordon @ Genesis/amp doctor too. He has sexually explicit MX406 content on his desk and car.


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## --Kei-- (Sep 8, 2011)

Cheers for the advice, will get on it once the unit arrives. Would be easy if it were as simple as adjusting some pots or you could buy the tuner module from pacparts etc.


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## an2ny888 (Jun 27, 2008)

this is interesting, please post the results if you pull this off, i'd like to mod my jdm drx9255 EXL as well


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## --Kei-- (Sep 8, 2011)

Well it turned up today and i can say that i am very impressed with it. As much as I liked my alpine, it makes the alpine feel a bit cheap and clunky. (not to mention the fact that it actually works) CD mech was a bit squeaky so i took it apart and gave it a quick clean up and re-greased the gears. Much quieter now, and happily playing away on my test bench without an issue. Radio is japanese frequencies as expected. It also came with everything from cage to plastic surround.

























One thing that caught my eye whilst i had it apart was that it has a denon processor. I thought that only the EX/EXL models had that. (The pictures I've got of the inside of an EXL are identical in every way, I cannot see a single difference anywhere)


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## an2ny888 (Jun 27, 2008)

hmm, how did you change the color to amber?


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## --Kei-- (Sep 8, 2011)

Display colour is changed by pressing and holding disp and pressing the 1 button (on the 6 radio presets, pressing 5 whilst holding disp turns the beep on and off too.) Got it fitted in the car this morning looks quite tidy and sounds fabulous.


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## estione (Jul 24, 2009)

Hmmm that does look pretty, Are you pleased with it so far?


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## --Kei-- (Sep 8, 2011)

Ecstatic with it. It has managed to exceed my expectations. I just wanted a unit that worked with the clarion changer that i had in the car and didn't have noise issues or remote problems. The old alpine picked up noise from the climate control stepper motors and the CD-mech also introduced some noise from the spindle motor. It had an intermittent remote/antenna output so i had to use a separate switch to sort that. It was also quite fussy about the brand of CD-R's used for home-made compilations.

I've turned the gain on my antique alpine amps right down to minimum and it's still a heck of a lot louder compared to the 7915. I suppose that's what you get moving from 0.5V preout to 4V. (amps are a 3553 and a 3566, which are fed though a 3672 active crossover)


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## an2ny888 (Jun 27, 2008)

so were you able to mod the tuner before you installed it?


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## --Kei-- (Sep 8, 2011)

Nope I've left it for now and I'll see how it goes for a while. I'd like to get hold of the service manual before i consider tweaking it. I noticed a pair of solder pads inside the unit marked USA which i'd guess are for surface mount resistors. Pin 77 on the main IC is supposed to be for switching the tuner destination, but from the picture i took of the mainboard, i can't see a connection at that pin.


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## --Kei-- (Sep 8, 2011)

Found this video of an Addzest tuning to worldwide frequencies and also found some info on the conversion process albeit in russian.
DRX9255 FM - YouTube

Here's the translated text although some words remain foreign:



> Here is the article is like a man tinkering with the radio:
> 
> That allowance, on which I remade, because there is clearly written that can be distributed freely on the territory of Russia, etc. publish the name of the author, but my amendment, which was skated on the 2 copies DRH9255, so that they consider the regularity and advise you to use!
> Inaccuracies in the article, and add / correct a signed text of the valves, so you must first COMPLETELY Read the full article, get to the core and get down to business!
> ...


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## an2ny888 (Jun 27, 2008)

looks like a daunting task


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## --Kei-- (Sep 8, 2011)

I'm keeping an eye out for a damaged/broken clarion unit to use the tuner board from as the process looks a bit too experimental.


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## --Kei-- (Sep 8, 2011)

Well, I've managed to find myself a spare unit for a good price. It is another addzest but as it'll be a spare I can perform the tuner tweaks without fear of ruining my radio. Watch this space for more info as and when the unit arrives. (probably some time next week as it is unlikely to be posted to me before monday)


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## Schramm (Mar 12, 2012)

Hello Kei,

I have the DRX9255 Japanese Addzest model and have attempted the conversion to US frequency band with some success. Conversion to the European band would involve similar steps. There are many internet forums with people wanting to know how to do this, but few threads with people sharing first hand knowledge and success. While the Clarion and Addzest are very similar, dozens of differences on the circuit board design and tuner to make this a daunting task; more than I anticipated. 

Since you already have two Addzest models, read on. The system controller IC is programmed and among many tasks acts as a divider network to control the PLL tuner IC. Initial destination area is set by a jumper located on the rear of the main PCB, opposite to the system controller. By moving a zero ohm resistor from JPN to USA near the system controller, it will bring pin 77 on the system controller from high (5 volts) to low (0 volts). It can also be moved other (EURO) to bring pin 77 to ½ VCC. This will effectively change the frequency range and spacing visible on the display.

Of note, there are two other jumper areas on the front of the main PCB marked USA. While the Clarion service manual makes no mention of these blank component areas, it does appear from the schematic that the traces are connected on the Clarion model. As such, I soldered two additional surface mount zero ohm resistors in place. No difference was observed.

At this point, you will still not be able to tune in any FM /AM frequencies because the front end tuner is different. Unfortunately, BL 1 880-1950B is discontinued and the schematic and component values are not indicated in the service manual. You can obtain data sheets for the individual Sanyo, Panasonic, and Toshiba IC’s and observe recommended circuit application and note differences of component values between USA and JPN design. Manufacturer's usually do not deviate, but this is an electrical engineering technical level. The easier route is to obtained an inexpensive Clarion model of similar vintage for parts and salvaged part 880-1950B. This is what I did. Unfortunately, the logic board obtained was mfg. 1994 and was rev 099-9967-03 instead of 099-9967-04 mfg 1996 and contained earlier generation Sanyo IC LA1192 instead of the improved LA1193. The earlier rev was different in other ways too. However, since the Pin-out was the same, I replaced the entire BL 1 880-1950B. FM now works with good reception. AM works marginally, no where near what it should be for a tuner of this caliber. Front end tuners are calibrated at the factory and are not easy to optimize without an oscilloscope or volt meter and signal generator. I have not tried to adjust any of the variable settings on the tuner yet. It is not really possible to adjust real time while in operation, once the shield is soldered in place and the tuner is reinstalled.

I still listen to AM talk radio in the car, often enough to be disappointed. I may try to obtain another parts deck for 099-9967-04 or try further experimentation, but am concerned because there are a number of component differences on the main PCB tuner area also. Without the Addzest service manual for direct comparison of component values against the Clarion Service manual it is difficult to know what should be further changed. I am curious if others have had better success. 

If anyone has the Addzest service manual send me a PM for trade. I already have pictures and can post some soon.


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## --Kei-- (Sep 8, 2011)

Cheers, that info will be a great help, by chance do you happen to know of any suitable clarion models from this era that can be butchered for parts? I've got a wanted ad on another forum for a broken clarion, but i think they are quite rare in the UK.

I think you may have trouble with an addzest service manual as it'll be in japanese scipt. I've got an addzest EXL owners manual and its mostly in kanji. I also have some bits of the mcintosh MX406 service manual, mainly circuit diagrams.

Some nice big pictures of the tuner board will be super.

Lastly, what are the IC numbers so i can get their datasheets? (I've got the sanyo LC7219 and Toshiba TA7372P datasheets already)


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## raulgz (Dec 29, 2009)

> I found this guide for a McIntosh unit which should be made by clarion so in principal it should be similar


suscribed to this post, really interest in this mods JP to EU Frec and US to EU


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## apotelyt (Nov 5, 2009)

raulgz said:


> suscribed to this post, really interest in this mods JP to EU Frec and US to EU


Me too. I too have an Addzest and looking to convert the JP tuner to US/EU


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## Schramm (Mar 12, 2012)

Addzest DRX9255 main PCB and tuner section highlighted. If anyone has the Clarion model, please post pictures highlighting the same areas for direct comparison.


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## --Kei-- (Sep 8, 2011)

Having had a look at the datasheets for the IC's on the tuner module you posted above, It looks like you can convert the FM tuner properly following the details given here.

Japan









US/Euro - there are 3 capacitors that are different off mix pins 6 & 7. (16pF on JPN & 10pF on US and the pair of 5pF on JPN become 6pF on US)









Coil spec

















The AM tuner is the LA1137 chip, its not quite as obvious, (ony had a quick glance) but the information is probably contained within the datasheet somewhere.


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## Schramm (Mar 12, 2012)

Kei,

You are on the right track! I previously studied the same Sanyo 1193M datasheet and according to the application circuit example, noticed the same differences for capacitors, coils, and inductors. The capacitors are easy to source. The Sumida coils could be modified by carefully removing the shield and adjusting the turn ratios per specification; provided you figure out the applicable ones on the circuit board to change. Unfortunately, they are not marked on the circuit board. The green air core inductor loses one turn on the USA and Europe model.

Attached are pictures of the USA version of a tuner that I swapped in. This was from a low end Clarion tape deck manufactured in 1994. The rev. was earlier at 099-9967-03 and there are clear differences on the board in other areas too. This may just be related to the earlier rev. design. I do not know. Hopefully this does not confuse anyone. The earlier generation LA1192 (no datasheet, discontinued) has less FM dynamic range so I may take the board back out and change some of the individual parts on the JPN tuner or try to obtain a different Clarion DRX_____ parts deck manufactured in 1996-1997 in Japan. A spare tuner from a Clarion DRX9255 would be ideal, but spares are still expensive and rare, negating the reason why most obtain the Addzest in the first place.

Unfortunately, this is just one application circuit. Theoretically, the AM sections are the same given the same AM frequency range in Japan, but I can't confirm this. Would need to see pics of rev. 099-9967-04 and a schematic to be sure. Of note, the Addzest main PCB is blank for C52 (am detect to ground tuner pin out). This is a 0.068uF capacitor on the Clarion schematic. Worth exploration.

All,

Again, if you have pics of a Clarion DRX9255 for comparison, please post or send a link. Contributors welcome.

Thanks.


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## --Kei-- (Sep 8, 2011)

I have the old clarion radio from my saab which is from 1995. The radio module in this image certainly looks similar, but i'd have to dismantle it to find out the part number and IC numbers.
Saab 900 Radio line-in mod <- shows the innards quite well.


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## --Kei-- (Sep 8, 2011)

Had a look inside my saab/clarion radio and its different to the site above, probably because its a european tuner with RDS, but most of the unit appears to be different. The radio seems to be split into 3 separate boards so that idea's out the window. I've got 3 spare vintage alpine headunits (2 of which are presently partially functional, but their tuners are good) Might have a look at their tuner modules.


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## --Kei-- (Sep 8, 2011)

Had a look at some other clarion service manuals for UK units from around the same period and i reckon that I might have to find a US model unit to get any useful parts as the UK stuff seems to be different. (Looked at an ARB2170 & a PU9358A) I can't find much over here that hasn't got RDS either which doesn't help.

The alpine headunit wasn't much help either as that tuner is totally different too. (number of turns in the coils that i could see were completely different. (but then diameter may also have differed too)

What unit did you manage to lift that early tuner module from?


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## Schramm (Mar 12, 2012)

Use the Part to Model Search at Consumer Electronic Parts and Accessories at PacParts, Inc. and find a Clarion model of similar vintage.


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## --Kei-- (Sep 8, 2011)

Well according to the pacparts site, there are 4 made in 1996:

CLARION ARX7270
CLARION ARX8270
CLARION ARX9270
CLARION DRX8275

I have found an ARX8170 in the UK which is in the list as 1995, but it does have RDS/EON. (those features may be on the mainboard, separate to the tuner module but i won't know until i get the manual or buy it and take a look) There's a service manual here, but i can't download it tonight as i've already done 2 from there today.


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## --Kei-- (Sep 8, 2011)

Got the schematics for the ARX8170 and it appears the euro model uses a different tuner and since the pin-out on the tuner board is different, it looks like a different mainboard too.









The 7170 has RDS too so probably uses the same or similar tuner over here in europe. The pro audio logo that you guys in the US get is replaced with an RDS/EON logo over here. Makes me wonder about the rest of the units in the list as almost everything had adopted RDS in the early 90's. Why they didn't have it on the DRX9255 is beyond me. (especially with it being top of the range)

Looks like I've got no choice other than to import a suitable unit from the US or find a broken clarion/mcintosh model to use for parts.


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## Schramm (Mar 12, 2012)

ARX8170 is a totally different pin out. The head unit I pulled the tuner from was Model 3580RC, made in Malaysia 1994. It was a piece of junk obtained for next to nothing. I presume the US models you mentioned would be good candidates considering the DRX9255 was made in 1996, but I cannot confirm with out seeing the service manuals. It is worth a try for parts.

The other option is to try and carefully modifying the turns on the coils, inductor, and change the capacitors in the FM section of the existing tuner per the LM7293 application circuit. Very delicate work. The board I swapped in does work fine as is for FM, but I may try this route and see if it further improves performance. In your case, since you have an extra DRX9255 for parts, I would recommend this option. If you can trace the tuner circuit board against the Sanyo application circuit and determine which component is which, then have a go at it.


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## --Kei-- (Sep 8, 2011)

I know its probably unlikely, but does anyone happen to know if any of these units were available in europe/UK without RDS?









I'd put up a wanted Ad but until i'm at 500 posts or a paid up member i can't se I'll just need to stay on the lookout. I might enquire with clarion service in the UK and see if by chance they have a tuner board.


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## HisHeirness23 (Jul 28, 2009)

Very interesting thread. Any idea if this can be done with a McIntosh MX5000? I've always wondered if you could swap out the tuner from an MX406 into an MX5000 to get the US frequencies.


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## --Kei-- (Sep 8, 2011)

Don't think its quite the same, might find that the HX-D1 tuner maybe the same as the MX5000. (there's a picture on page 1) You'd have to find out what the board number for your tuner is to be sure.


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## HisHeirness23 (Jul 28, 2009)

--Kei-- said:


> Don't think its quite the same, might find that the HX-D1 tuner maybe the same as the MX5000. (there's a picture on page 1) You'd have to find out what the board number for your tuner is to be sure.


Thanks, I recently purchased an MX5000 and was inspired to try out a possible tuner swap after reading the blog you posted.


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## --Kei-- (Sep 8, 2011)

Technically speaking the process of converting the tuner is the same, just the layout of the tuner daughter board is different to the DRX.


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## Schramm (Mar 12, 2012)

The HX-D1 and HX-D2 tuner board have 23 pins as evidenced in a picture earlier in this post and in their respective service manuals. I am not sure what similarities are shared with the MX5000, but you would certainly want to do the research on the MX5000 before risking damaging a significantly more expensive head unit.


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## --Kei-- (Sep 8, 2011)

I said it would probably be this week for that spare addzest unit to turn up, but I've not been able to get in contact with the guy yet so it might be a while longer.

Luckily one friendly member on here is sending me a broken US model DRX which will have the tuner board you seek. Once it's here I will take some detailed photos of the tuner board for you, just have to wait for it to cross the pond.


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## HisHeirness23 (Jul 28, 2009)

I took apart the MX5000 to see if what the tuner looked like:











Here is a pic of the HU's guts with the CD player removed:




















I also took apart my MX406 and MX4000 and those two shared a lot of similarities. Most notably, they had similar tuners (both US Freq.). I do believe it was mentioned here, but the MX406 has a Denon processor, while the MX4000 does not. Of course, the MX4000 requires an external DAC, which might explain its absence.

I am going to keep reading up on this and continue doing research, but if anyone has a service manual for the MX5000 that they could send me (email/PM), that would be great.


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## --Kei-- (Sep 8, 2011)

The tuner in your MX5000 matches that of the clarion HX-D1. (so an MX406 tuner won't work as that is the same as the DRX9255) The control of the FM tuner frequencies is via the three coils. (the open air one you can see and 2 more to the right wrapped around a white plastic core) There are probably some jumpers somewhere on the mainboard that determine the control of the bands. (setting the pin voltage on the controller IC) The datasheet for LA1781M has all of the relevant details. (its a single chip for both AM & FM, where as the MX406/DRX9255 are discrete parts for each)

Anyway the US DRX was shipped on saturday so should be here before the end of the month.


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## HisHeirness23 (Jul 28, 2009)

--Kei-- said:


> The tuner in your MX5000 matches that of the clarion HX-D1. (so an MX406 tuner won't work as that is the same as the DRX9255) The control of the FM tuner frequencies is via the three coils. (the open air one you can see and 2 more to the right wrapped around a white plastic core) There are probably some jumpers somewhere on the mainboard that determine the control of the bands. (setting the pin voltage on the controller IC) The datasheet for LA1781M has all of the relevant details. (its a single chip for both AM & FM, where as the MX406/DRX9255 are discrete parts for each)
> 
> Anyway the US DRX was shipped on saturday so should be here before the end of the month.


How about the HX-D10? Is the tuner the same as that or is that much newer?


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## chithead (Mar 19, 2008)

--Kei-- said:


> Anyway the US DRX was shipped on saturday so should be here before the end of the month.


Wholly moly! I hope it gets there before then


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## --Kei-- (Sep 8, 2011)

i got my hands on the US DRX9255 now.









I've also noticed some internal differences (apart from the obvious tuner differences)

Clarion









Addzest









I also noticed why the CD-mech doesn't work (or at least part of the reason) There was also a fair dent in the chassis behind the two voltage regulators on the right which is what caused the load eject problems as its bent the CD-mech housing. Someone at some point has been doing a lot of soldering around some of the ribbon connectors and the one on the right that links to a microswitch is not in good shape. The sled motor for the laser is also very well greased.

Damage from the dent









Ribbon damage.


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## HisHeirness23 (Jul 28, 2009)

Got back to looking at the board and I might be onto something...










Notice that it gives three different codes/combinations to choose from, dictating either High or Low on the microcontroller. If you look at the values for "J" you will see that both are "H" (corresponding to 0 ohm resistors on R619 and R620). This unit came from Japan, so maybe that could be for that. The "K" and "U" might be codes for other countries or regions. I am not sure.

Any input on this would be greatly appreciated!


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## --Kei-- (Sep 8, 2011)

That could be right. Also note there are model numbers listed. (PA2346, PE2488, PB2345) The label on the bottom of the chassis should tell you what model yours is. (for example my addzest unit is PA-2212A and my clarion is PE-2221B) With the service manual you could find out what pins 8 & 9 do on that controller chip.

Like this snippet from the MX406 manual









While I am posting, here is a comparison of the bottom of the pcbs

Clarion









Addzest


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## HisHeirness23 (Jul 28, 2009)

Got the Tuner Pack from McIntosh yesterday





































Compared to the Tuner Pack on the MX5000, it appears that there is a second set of coils. Also, the original Tuner Pack was 802087FT whereas the replacement Tuner Pack as 802087GH.

The pic below is the original for reference


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## --Kei-- (Sep 8, 2011)

That replacement certainly looks like its a US tuner. Now all you need to do is figure out which jumper(s) to move and you should be set.


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## --Kei-- (Sep 8, 2011)

I robbed my old alpine 7903 of the two regulator transistors i needed to fix the spare addzest (unit number 3) and rebuilt it. It is now also up and working perfectly. Not yet tested the c-bus output on it, but I now have 3 working units.









Also dismantled the clarion and took the radio module out so i could get a closer look at the coils so i can look into converting the addzest tuner to work with US frequencies. Here is a US tuner board from a DRX.

















The coils


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## Schramm (Mar 12, 2012)

You are on the right track. As Kei mentioned, the service manual for your McIntosh should confirm what pins 8 and 9 control. As indicated on the circuit board, it appears they control the initial area set, i.e. clock frequency range and stepping for the phase lock loop IC. I do not have the McIntosh service manual, but think it safe to assume that J = Japan, U = USA, and K = Europe. You will need to unsolder and re-solder the zero ohm jumper(s) to the new desired configuration. Pay attention to what must be H (+5 volts) and low (0 volts). Based on a quick glance of the PCB diagram, I gather that for INIT1, pin 8 is H for Japan and USA. So no change to R621 or R619 is required for USA area. For INIT2, pin 9 is high for Japan but low for USA. *This means you will need to unsolder the zero ohm jumper on R620 and simply move it to R622 for USA area.*

Tip: Use super fine grade de-soldering wick and as little heat and force as possible to avoid lifting the copper traces on the PCB during removal. When re-soldering, a very small drop of cyanoacrylate (superglue) can be used to position of the SMC resistor prior to soldering.



HisHeirness23 said:


> Got back to looking at the board and I might be onto something...
> 
> 
> 
> ...


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## HisHeirness23 (Jul 28, 2009)

Schramm said:


> You are on the right track. As Kei mentioned, the service manual for your McIntosh should confirm what pins 8 and 9 control. As indicated on the circuit board, it appears they control the initial area set, i.e. clock frequency range and stepping for the phase lock loop IC. I do not have the McIntosh service manual, but think it safe to assume that J = Japan, U = USA, and K = Europe. You will need to unsolder and re-solder the zero ohm jumper(s) to the new desired configuration. Pay attention to what must be H (+5 volts) and low (0 volts).
> 
> Tip: Use super fine grade de-soldering wick and as little heat and force as possible to avoid lifting the copper traces on the PCB during removal. When re-soldering, a very small drop of cyanoacrylate (superglue) can be used to position of the SMC resistor prior to soldering.


Thanks for the advice. Unfortunately, I contacted McIntosh USA and they did not have any Service Manuals for the MX5000. I did, however, get a copy of the User Manual (in English) which is nice to have. Also got a new escutcheon to replace the old one which had broken tabs for the silver end trim pieces. I am currently waiting to hear back from Matt R as he has an MX5000 with US FM frequency band, so I want to make sure that I am not going to ruin the board.


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## Schramm (Mar 12, 2012)

Observe the AM-ST outlined section on the rear of the main PCB of the DRX9255. The Addzest has plenty of components in this section, but the Clarion is blank. There are other differences on the board also.


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## --Kei-- (Sep 8, 2011)

Email is on its way, may take a while as its 30mb. Had to split it in 2 as it was too big to send as one.


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## --Kei-- (Sep 8, 2011)

Finally figured out why i didn't have the full AM band available. I had switched the band mode to "outside US" so i can tune in 0.05MHz steps for FM, this adjusts the AM band back to 530-1629KHz. If you leave the band spacing as default US, the AM band is the full 530-1710KHz. AM seemed to work very well during my testing.


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## --Kei-- (Sep 8, 2011)

Noticed a jumper in the top right corner that i believe enables the auto-antenna function that the Addzest has. (antenna up while the radio is on and down whilst playing cds)









I've been working out the parts i need for replacing all the electrolytic capacitors and getting the additional parts for the aux in. Trouble is very few capacitors are physically small enough as they can only be about 2mm wider in diameter (about 7mm for the most part) and they cannot be any taller than 8mm, and where the cdmech has low parts on its pcb, less than 7mm. I've compiled a list of caps that are mostly panasonic FC and sanyo OSCON SC/SH. The problem is that most normal capacitors are like the two on the left in this picture. (one from the DRX is on the right)


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## --Kei-- (Sep 8, 2011)

The new capacitors are now here and i've finally realised the "fun" job I'm in for.


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## --Kei-- (Sep 8, 2011)

Tone control and preamp are now done. Old on the top and recapped beneath.

















The side of the main pcb which is covered by the preamp/tone boards is also complete. I've reassembled it and got it running a cd sounding very nice. Not even half way through yet though.


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## chithead (Mar 19, 2008)

That's a lot of caps...


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## --Kei-- (Sep 8, 2011)

The dac is now done too, going to get some more done when i get back from work.


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## --Kei-- (Sep 8, 2011)

Spent this evening working on it and managed to finish replacing the capacitors in the headunit.


















Going to look at the cd-mech board as there are a few caps on that and then look at the dc-dc converter. (although i don't think I've got any 200uF caps in my collection so may not be able to finish) I've got the bug good and proper though as i'm contemplating doing my amplifiers too.


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## --Kei-- (Sep 8, 2011)

I ended up butchering the spare addzest and the damaged cd-mech from the clarion as neither were happy to work properly but parts from both got the clarion going reliably. I got the auto antenna function working after some studying of the two boards.

Pin 5 on the main control IC goes high (5V) whilst the radio is on and goes low on other modes. It uses the same circuit layout as the amp remote but it is separate. Pin 40 is the amp remote which goes high while the unit is on and low when off. Pin 5 on my american unit wasn't going high so i've piggybacked off the AM-ST section (which isn't used in the US model) a 5V switched voltage that does the same as the main IC should. (i had to disconnect the base of Q215 from its connection to pin 5 to make it work, linking the base to the section above via a very fine wire.)

Necessary components:
Q214 2SB1237
Q215 RN1406
R218 10K 0603 SMD resistor
R220 1K2 1/4W resistor
R224 10R 1/4W resistor

In orange/red I've highlighted the automatic antenna components. In yellow I've highlighted the amp remote components.


















Also looked into the AUX input after getting some photos of an MX406 (thanks again Steve) I can now categorically state that there is virtually no difference between the MX406 and the DRX except for the front controls, CATS and the aux input. (JDM to US comparisons aren't id I also now have a full component list for creating an aux input on a DRX.

*Capacitors - SMD 0603 case size - Ceramic multilayer (service manual says CH, not sure if this refers to dielectric type)*
C307 - 0.047uF
C308/310/313/315 - 33pF
C309/311/312/314 - 4.7uF 35V - Though-hole no higher than 8mm and no more than 6mm in diameter

*Resistors - All SMD 0603 Case size*
R306/328 - 22K
R310/311/313/314/315/317/318/319 - 10K
R307/312/316/329 - 100K
R348/363/364 - 1K
R346 - 33K
R347 - 120K
R354 - 330R

*Diodes - All SMD*
D300/301/302/303/308/309 - MA111 (MA2J111) - no longer available equivalent part - CD1005-S0180 - Bourns - SOD-323F case

*Transistors - All through hole*
Q300/302 - 2SK372 - no longer available equivalent part - 2SK170

*ICs - All SMD*
IC301 - NJM4565M - Might be able to upgrade these parts to LM4562
IC305 - NJM4558M

No 0R jumpers appear to be required. All you need to do then is move the RCA outputs to the MX406/EX position above the clarion multipin connection (cut the tab off the top panel) and fit an RCA cable in the position. You may be able to buy the original cable from mcintosh. (i'm looking into this as it will look tidier than me making my own)

I also took a look at the DC-DC converter today and swapped the caps that i could. (didn't have any 220uF caps so left them as they were)









I swapped the NJM4580's off for the OP275's from the addzest. I'll lookat swapping them all out for LM4562's at some point. (the others on there are uPC4570, there is another on the tone control and there are 2 OPA2604 in the DAC I/V)









Also noticed a difference between the US and JDM cd mech boards too. The US uses a cera-resonator and the JDM uses a crystal. Notice the part numbers differ too. (even though there appear to be no other differences between them.)


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## an2ny888 (Jun 27, 2008)

i seem to remember the jdm drx 9255 having an auto loudness function, did you disable that too?


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## --Kei-- (Sep 8, 2011)

The clarion must also have it, as there were no differences in that area of the board. (those comparison shots in post #57 of the tone/preamp is the US compared to the addzest) Apart from the different opamps and a single inductor for the phone interrupt, there isn't a single difference between them)

There is a loudness tap on the volume pot and LOUD is mentioned in the flow diagram. From what i can tell, loudness is controlled by the two 0.33uF capacitors and the two 10K surface mount resistors. The best bit is that the McIntosh MX406 also has this feature. (easiest way to tell is check the solder pads for the volume control, if there are 8 you have a loudness tap, if there are only 6 you don't.) Removal seems to be a simple case of removing R511, R551, C550 and C510. (just taking out the capacitors should be enough as it'll break the circuit)


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## abdulwq (Aug 17, 2008)

does it worth spending this much time and money?


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## --Kei-- (Sep 8, 2011)

Fitted new LM4562 opamps all round on the preamp board. I've left the dac i/v as is with the standard opa2604 as they seem to do a good job. (and they are certainly superior to the 4560, 4570, 4580's that are usually found in most other headunits)









Also finished work on the DC-DC converter, fitting panasonic FM in place of the originals.









Presently got the unmodded addzest from the car playing side by side with the clarion to see if the changes really have made a difference and also to see if the changes have affected the operating temperature as these new opamps seem to run quite hot.


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## Schramm (Mar 12, 2012)

This is very impressive. Some may think this is overkill, but electrolytic capacitors do have a shelf life and low ESR versions are now available for low cost. Better op amps have been introduced also, but changing them requires a careful matching of electrical parameters. It seems there is a lot of experimental advice on forums comparing the last nth degree of performance without this consideration. I say this as I think about upgrading the op amps on my McIntosh amp (from BA15532 Rohm to ?). Let your ears be the judge and do let us know how this changes the sound quality with an A/B comparison.

Perhaps you have seen this link, but it also describes disabling the auto loudness feature. Use Google translate from Japanese. HILO 's HOMEPAGE


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## abdulwq (Aug 17, 2008)

Can you tell me if the bass treble knob is missing then what has been modified?
I bought it from japan and it came like this.
Anyway you have nice work going on


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## --Kei-- (Sep 8, 2011)

Having run them side by side for a few hours solid, they are both ran at virtually identical temperatures so I think things are OK. Using 2 of the same cd playing (I only have one that i have two copies of, which is sting - ten summoners tales) back at the same time with the left channel coming from one unit and the right channel from the other i have had the chance to make a rough comparison. The difference between the two is not massive but the upgraded unit has greater detail to the mids and highs and slightly greater separation to the instruments. The original doesn't sound bad by any means, merely smoother and ever so slightly veiled. Noise wise there is no audible difference, both units are silent with no audible hiss. (even though one has vastly superior capacitors in the psu) The real test would be in the car, but i already praised the addzest for being as near to silent as it gets so if the clarion is better than that its unlikely i'll know about it.

Mods wise the clarion has a full new set of electrolytic capacitors some having been replaced with plastic film. The new capacitors have all been low esr and mostly 105 degrees rated. (most of the caps are sanyo os-con and panasonic FC the psu has mostly panasonic FM, the film caps were wima MKS. The original opamps were uPC4570 and NJM4580 which i changed for LM4562. The addzest uses OP275 and NJM4580 and a single uPC4570 on the tone control. I like to keep the auto loudness function (and i upgraded it with film caps which should make an improvement) I also like to keep the tone controls too, so they are still present and working.


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## --Kei-- (Sep 8, 2011)

Well i just swapped a pair of BA15532 (rohm part number for the more common NE5532) with a pair of the LM4562's i had spare. Results have been very impressive so far, much more obvious than the changes to the clarion/addzest. I put them in the preamp of my alpine 7915, there are still 9 opamps that could be changed yet though, mostly 4560, 4580 and 5532. (i've also fully re-capped this unit too which has fixed all the problems i had with it)


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## --Kei-- (Sep 8, 2011)

Just put the unit in the car and it turns out i've piggyback the auto-antenna 5V switching source off part of the seek circuit as the aerial goes up and down whilst seeking. Pulled one of the japanese units out and moved the location jumper to US and it stops the 5V output on pin 5 of IC600 for M-Ant meaning no automatic antenna with US radio frequencies.


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## HisHeirness23 (Jul 28, 2009)

Kyle, I have been unsuccessful in being able to convert the MX-5000 to US FM frequencies. At this point, I think I am going to give it a rest. Not having the service manual is turning out to be the biggest reason that I cannot confidently perform much of the work. I have been told that there are MX-5000 head units with the US FM band, but I cannot figure out how to do so. I fear that it isn't as simple as moving a 0 ohm resistor, and that it requires a different chipset. Your hardwork has paid off, and maybe someday I will be able to say the same. I would love to see pictures of your HU in your car and functioning.


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## --Kei-- (Sep 8, 2011)

That is disappointing to hear steve. If there was more information available on the MX5000 we'd stand a better chance but I haven't been able to find anything, not even for the HX-D1. Presumably you didn't hear back from MattR? Its a bit like my aux in attempt on my DRX, which hasn't worked out properly.

My build thread has all of the pictures of my install.


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## cartion (Jan 26, 2012)

I have a Mx5000 and i am in the uk, I also have the annoying japense band radio, meaning it only goes to like 89 and i get one radio station.

So if anyone find out how to change the frequency let me know.i heard on the mx406 its just a case of setting the HU with the knobs.


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## coomaster1 (Jul 22, 2010)

Hi, Kei, Do you still have that alpine 3672 crossover in your car in use.If not I was looking for one. If yours is not for sale.Do you know of another one for sale .thanks


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## --Kei-- (Sep 8, 2011)

I still have my 3672, though i doubt I'll ever part with it. (quite a lot of people have asked over the years) It's the central part of my system and wouldn't work without it. If you cannot find the alpine, try looking for a JVC KS-N60 which is nearly identical. (does have some extras, like parametric EQ for the sub)

While I'm posting here, I finally got around to pulling the unit back out of the car to sort this out. (the brightness and sharp sound was beginning to get to me) Took some fiddling to get the one cap in place under the tone pot, but it all came together. I used 68nF wima MKS which seems to have done the job as they sound much smoother now. Sounds like a completely different opamp, though it still runs reasonably warm its a fair bit cooler than before as i didn't manage to burn my fingers.


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## zeeman (Feb 4, 2014)

Not to bring this thread back from the dead.....

Did anyone ever figure out how to convert the MX5000 tuner to US bands?


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## Schramm (Mar 12, 2012)

I can't speak to the MX5000, but it was not designed for the US market.

There is one thing I should add to this thread regarding the DRX9255. The diversity tuner system it has uses two FM antennas and circuitry to sense the strongest signal input. Usage of a second antennae (often built into the rear windshield) can improve FM reception in some situations. However it is optional and very few cars have the capability to use the diversity tuner set-up. The diversity circuit that selects which antennae has the strongest FM reception resides on main board. I am not sure if the changes effected the diversity circuit functionality.


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## zeeman (Feb 4, 2014)

Schramm said:


> I can't speak to the MX5000, but it was not designed for the US market.
> 
> There is one thing I should add to this thread regarding the DRX9255. The diversity tuner system it has uses two FM antennas and circuitry to sense the strongest signal input. Usage of a second antennae (often built into the rear windshield) can improve FM reception in some situations. However it is optional and very few cars have the capability to use the diversity tuner set-up. There is some additional FM receiver circuitry in the Addzest main board. I suspect it would also need to be converted or re-tuned in addition to the main Tuner for the diversity system to function.


That is interesting thanks for the info.


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## Schramm (Mar 12, 2012)

Refer back to posts 41, 45, 48, 71. It still looks possible.


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