# Modded DENON DCT1



## Matt R

This HU belongs to Jason Winslow (thehatedguy). We both thought it would be cool to show some of the modifications that I did to it. I dont have the schematics for this unit so it's a bit of a guessing game but it's obvious what most of the important parts are. I changed the I/V converters, the output opamps and the coupling caps. I also added a good bit of power supply decoupling caps to the digital and analog sides of the dac and output stage.

Here are a couple of before pics

















parts removed

















and the put back


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## thehatedguy

*Re: Moded DENON DCT1*

AH the goodness!

Any voltage regulator goodness?


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## thehatedguy

That third picture, I was like what the hell is that pile of crap from? Then I saw. And then I saw the sprawling capacitor city going on.


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## stills

nice

gotta be one of the prettiest head units out there.
lol i can barely tack two wires together sometimes


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## thehatedguy

Wonders what a new clock would do for it?

You guys like this...just wait to see what he's posting next. Probably the only one in the world right now...


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## Matt R

*Re: Moded DENON DCT1*



thehatedguy said:


> AH the goodness!
> 
> Any voltage regulator goodness?


It doesnt seem to use any 3 terminal regs so it must be all discrete, which is definately a good thing. That means no go without schematics though. :~(


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## thehatedguy

At least you had schematics for one of the things...lol.


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## req

crazy. so how do you figure out what components to change in order to make a difference?


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## thehatedguy

Change them all!

Seriously though, what Matt normally does when he is doing some heavy mods is make a change, listen. Make a change, listen, make a change, listen. So it can be very time consuming. And then you have all sorts of flavors for the components you replace, like opamps. They all sound different. You can do some research like on the headphone forums to get an idea of what an opamp in an ideal setting could sound like. Then you buy a few and put them in and listen. The headphone crowd is really into this sort of thing because that is all you are listening to is the opamp, so it's easier to hear differences there.

Then you have caps...and that is a whole 'nother can of worms. Ideally you would want to use film-type caps everywhere you can. But film caps are rather large for their given values. So you have to use electrolytics when space and large values are needed. For electrolytics, I usually think, "If it's good enough for Nelson Pass, then it's good enough for me." So that usually means Panasonic FC or FM in the power supply and Elna Silmics in the signal path. The Panasonic caps are awesome- low low ESR and ESL and extremely low ripple current. And they are pretty inexpensive and easy to get at Digikey. The upside is in the signal section you can bypass/parallel the electrolytics with a small film or mica cap to get more of the film sound.

For this deck I didn't have any particular components in mind. I know Matt had a good recipe for the Denons that he liked, and I said do whatever you think will sound good. I think we have similar ideas on what sounds good from hanging out with him and judging with him over the years. So trusted he would do me right.


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## Matt R

The BB1704 dac uses dual power supplies. One for the digital side and one for the analog side. The digital side is more prone to hi frequency noise so adding .01film decoupling right at the device can make a noticeable difference. Most HU's use ceramic caps for local decoupling which don't have near as good of a response time at hi frequencies. In other words, hi freq noise is lowered considerably by using film decoupling caps. 

I have done like Jason said and built opamp based headphone amps to compare different opamps. I'm not here to argue with people about one opamp vs another but I deffinately have my favorites.


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## Melodic Acoustic

Pure sweetness!! I have one of these modded Denon in my hands also.:tongue3:


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## thehatedguy

Mine has four more bits in the DAC than yours has


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## Melodic Acoustic

thehatedguy said:


> Mine has four more bits in the DAC than yours has


LOL:laugh:

You know i hate you right?

hmmmm 4 more not that they matter. LOL


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## thehatedguy

Come on, yours only does 20 places past the decimal...4 more places is that much more...lol.

Plus mine has a black face plate 

But Matt said this one would be really similar to the one he did for you that sounded so awesome. I haven't gotten them yet so I can't tell you anything about how it sounds.


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## Matt R

Yeah Mark called me after listening to his on a home type set up and seemed happy with the results. I liked it much better too!!


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## SQ Audi

Mine goes up to 11


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## thehatedguy

Why not just make 10 1 louder?



SQ Stang said:


> Mine goes up to 11


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## thehatedguy

I know it's not a MX5000 or some super fancy tubed home player from AMR, but it's gonna have to do do for now.

Poor me.



Matt R said:


> Yeah Mark called me after listening to his on a home type set up and seemed happy with the results. I liked it much better too!!


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## Melodic Acoustic

thehatedguy said:


> Come on, yours only does 20 places past the decimal...4 more places is that much more...lol.
> 
> *Plus mine has a black face plate *
> 
> But Matt said this one would be really similar to the one he did for you that sounded so awesome. I haven't gotten them yet so I can't tell you anything about how it sounds.


See now your just making fun of me.:laugh:

But man it does sound nice, smoother then before, but yet more detailed and revealing at the same time. Not sure how Matt did that, but man I'm sure glad he did.epper:

Can't wait to listen to the Eclipse that is on its way back to me now. Matt said it sounds really nice. I liked the sound of it before, but after hear the Denon and DRX9255 Matt did for me can't wait to hear the improvement he has made in the Eclipse.


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## Salami

thehatedguy said:


> Why not just make 10 1 louder?


Because some times you just need a little extra. You know those times when it is at ten and you just need a little bit extra? That is why these go to eleven. For when you need a little extra to push it over the top, just turn it up to eleven.


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## SQ Audi

Salami said:


> Because some times you just need a little extra. You know those times when it is at ten and you just need a little bit extra? That is why these go to eleven. For when you need a little extra to push it over the top, just turn it up to eleven.


:beerchug:


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## thehatedguy

How much blacker could the face plate be? None. None more blacker.


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## danno14

> I know it's not a MX5000. Poor me.


Nuk nuk!!!


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## Matt R

thehatedguy said:


> I know it's not a MX5000 or some super fancy tubed home player from AMR, but it's gonna have to do do for now.
> 
> Poor me.


****!!! The Denon has the widest circuitboard traces i've ever seen in a car piece. Very well built, I guess thats what you get when a home manufacturer makes a car piece. The mounting of the cd mechanism is second to none as well.


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## thehatedguy

I have some Marantz car amps  I should bring them with me so you can check them out. I think you would dig them- outboard power supply, 2 transistors and all discrete components.


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## SQ Audi

Hey Matt, what do you charge to mod an H701? Sorry for the thread hijack.

You can pm me or email me at [email protected]


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