# Help finishing my car/pro audio benchtop



## fertigaudio (Jul 18, 2010)

Hi,
I need your guys help for forthcoming projects this winter (deployed and bored).

I have thus far:
MS8220R 3 5/6 TRUE RMS DIGITAL MULTIMETER
Laptop with ROOMEQ RTA, WT3 software, box builder, horn resp. etc.
WT3 tester and bench setup (freeair and gram loading)
Behringer ECM3000? test mic with calibration
Rolls - mic stand, pre amps/phantom mic power, cables
Sorensen Raytheon 20V 80A power supply (super sensitive and ripple free) My baby  has its own breaker off the house box
Peavey 1 channel 31band +12 -18 dB rack eq
Peavey 2 channel PV900 rack amp (had been building/testing 18 pro subs with it)
Boxes full of car audio parts and cable for test scenarios
Behringer small 4 channel mixer for RCA and balanced outputs
10 amp Astron power supply for small stuff.
varous soldering irons/guns parts bins, old capacitors that need tossed
itellipower 80 amp RV charger (may sell it)
complete outfit of tools
Just installed an 8ft chopping block benchtop (craftsman).
*Fire extinguisher*

Questions.
Should I get a variable .1~volt increment tone generator? I have a laptop with calibrated outputs for this right now.
Which scope used and affordable 1-200
Suggestions on stuff I have? I have used P-Mastech stuff for 3 years now and though they are not a big company their stuff is really nice and cheap 

What I want to get/build.
.5cf 1cf 1.5cf test enclosures
12U portable RACK with casters
8 or 12 dummy loads from parts express 4 and 8 ohm
Build reference test monitors/small sub
Oscilloscope needed to test THD+N
Reference CD's (bass mekanik only cause it reminds me of the 90's, classical definitely!, standard tones, need input but i can search)

I know its no dream lab but its what I have, just wanted to see what industry insiders/CA&E veterans thought.


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## chad (Jun 30, 2005)

Get Dale Load resistors. They are worth it.


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## fertigaudio (Jul 18, 2010)

chad said:


> Get Dale Load resistors. They are worth it.


the man, myth, legend... nuff buttering you up... i heard you were the man to talk to. Thanks.


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## chad (Jun 30, 2005)

LOL thanks. Another thing I do is have BNC's on my load banks that I attach to the scope to watch it under load. I have 3 neutrik NL4's on the bench one is amp out, one is speaker in, the other is load/scope in. then I have a short NL4 to NL4 whip to attach the bench amp to the bench speakers, I also have a dual naner to NL4 whip that's longer so I can feed a speaker cab, feed the loads with a amp, feed the speakers with an amp, etc. this patchbay saves a LOT of time. I have adapters that adapt the naner connector to 1/4" bare wire, NL4, etc.

Your setup is what's ergonomic for you, some tech like the test gear up and in front of them like brian (audiogodz1 here.) whereas I prefer my test gear off to the right side, split between on the bench and below the bench racked up.



















Power is below and to the right.....










Computers hang on the left side.


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## fertigaudio (Jul 18, 2010)

I see a 10 meeter and maybe a 2 meter, you licensed or in it to mud duck people. 

I like the rack, Lamda... nice. I want to base my gear like that howerver have a 2 gauge bus running to the bench top for quick at your fingertip power.

Hope you have trained your cat to not chew wires (last pic) reminds me of Griswold family Christmas (Natl Lampoon Christmas)

Studio mic? Just curious.

From the look of the UPS and shortwave/10/12/2 Meter Bands your ready for an apocalyptic meltdown. 

Dig your setup man.

edit: is that the same behringer mixer lying against the back wall? I have that one too, lol great for balaned input converison and preamping.


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## chad (Jun 30, 2005)

Radio wise in that pic, the left is a Cobra 29LTD that has been removed and replaced with an alpine CDA9856 for tuner/CD playback. There's a Radio shack scanner in the middle and on the right is an all-band all-mode Yaesu FT-857D. The main part of hte radio is under the bench above the power supplies and close to the antenna feed-thru. the computer on the left primarily runs XP whereas the one ont he right is Linux the one ont he left has a TV tuner card so it's used for televisiona nd ham radio stufff such as running HRD along with SSTV/RTTY stuff.

HRD:


















I don't do a lot of 12V repair so i dont' really need the 12V bus across the bench.

The cat has been around electronics for a LONG time, he has never been much of a chewer, maybe he learned his lesson on his own once 

the mic is for the radio rig..... I dig big audio, I used to work in broadcast. Some of the older hams slap my hand often for being a bit too loud.

LOL UPS, that keeps the things running while the 20KVA generator spools up and for much longer if needed, that bank of 3 batteries under it, yeah, the stock batteries did not live up to my expectations  










I live in the sticks but I also provide the emergency communication and direction for the storm spotters in my county, I need power 100% of the time.


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## fertigaudio (Jul 18, 2010)

I am not familiar with the stuff on top the bench can u run me a list of all the stuff you have to give me point to start on more testing equipment. Tecktronix? Hitachi? BK? since audio is in the 0-20khz range what meter would be descent, not sure i will do any more ham/cb/amateur stuff, just audio until i go back looking for more stuff to play with.


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## fertigaudio (Jul 18, 2010)

chad said:


> Radio wise in that pic, the left is a Cobra 29LTD that has been removed and replaced with an alpine CDA9856 for tuner/CD playback. There's a Radio shack scanner in the middle and on the right is an all-band all-mode Yaesu FT-857D. The main part of hte radio is under the bench above the power supplies and close to the antenna feed-thru. the computer on the left primarily runs XP whereas the one ont he right is Linux the one ont he left has a TV tuner card so it's used for televisiona nd ham radio stufff such as running HRD along with SSTV/RTTY stuff.
> 
> FANCY
> 
> ...


REPLIES IN CAPS, oh and believe it or not I am from the north and i have no accent. :laugh:


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## chad (Jun 30, 2005)

No amplifier. 3 of us chipped in and bought/rebuilt a Gonset 2M 500W amp I used on a beam on a telescope mount to hit the ISS, if it piles up I'd kick that on, One astronaut commented on me trying to burn a hole in the side of it  We sold the gonset though, the price was right.

On HF the Yaesu does 100W stock, 50W on 2M and 30 on 70CM. When the bands are open I can generally talk to the folks I can hear on 100W, central South America and Australia are common contacts even with a modest .64wave vertical.

You can throw all the power you want into a dummy load and nobody will hear you, a well engineered antenna setup is essential. Knowledge of speech processing goes a long way too.


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## fertigaudio (Jul 18, 2010)

would this be a good scope for testing thd? it has digital out also
http://cgi.ebay.com/Tektronix-2211-...nalog-Scope-/140436632280?pt=BI_Oscilloscopes


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## envisionelec (Dec 14, 2005)

fertigaudio said:


> Hi,
> I need your guys help for forthcoming projects this winter (deployed and bored).
> 
> I have thus far:
> ...


I have an Instek GS-6103 dual 100MHz analog scope with measurements that I'm not using anymore. The display is nice and bright, but there is a bit of instability at startup until it warms. Nothing major. I haven't investigated and I bought a new DSO because I needed the space. All functions work correctly and it's rather pretty with its soft-touch buttons and green LEDs. The plastic has yellowed a bit under my fluorescent shop lights...

How does $75 plus shipping sound? I'll pack it with that Foam in place stuff. PM me.


Cursor Readout - Settings Memory - Time Base Auto-Range - Counter 100 MHz - Delayed Sweep Cursor Readout with 7 Measurements Panel Setup Lock of Digital-Control Functions 10 Sets Memory for Front Panel Settings (GOS-6103 - GOS-6103C) Time Base Auto-Range (GOS-6103 - GOS-6103C) Built-In 6-Digit Universal Counter (GOS-6103C) Buzzer Alarm LED Indicators TV Synchronization Trigger Signal Output Z-axis Modulation Input SMD Technology


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## fertigaudio (Jul 18, 2010)

envisionelec said:


> I have an Instek GS-6103 dual 100MHz analog scope with measurements that I'm not using anymore. The display is nice and bright, but there is a bit of instability at startup until it warms. Nothing major. I haven't investigated and I bought a new DSO because I needed the space. All functions work correctly and it's rather pretty with its soft-touch buttons and green LEDs. The plastic has yellowed a bit under my fluorescent shop lights...
> 
> How does $75 plus shipping sound? I'll pack it with that Foam in place stuff. PM me.
> 
> ...


Not a bad price at all, PM sent.


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## envisionelec (Dec 14, 2005)

fertigaudio said:


> Not a bad price at all, PM sent.


PM responded.

I paid $150 for it in 2006(?). I liked it because of its very good resolution of fast rise times which I needed for testing power supplies and amplifiers. However, I needed a capture mode which it doesn't have. Truth be told, I never used a DSO until a couple years ago when I started designing my own stuff. If you decide to get it, I think you'll be quite satisfied.


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## fertigaudio (Jul 18, 2010)

envisionelec said:


> PM responded.
> 
> I paid $150 for it in 2006(?). I liked it because of its very good resolution of fast rise times which I needed for testing power supplies and amplifiers. However, I needed a capture mode which it doesn't have. Truth be told, I never used a DSO until a couple years ago when I started designing my own stuff. If you decide to get it, I think you'll be quite satisfied.


I originally wanted it to test THD and notch filters. I think this is way more than I need. I am only doing audio so the 100 mhz is overkill, I could get away with a 5 MHZ unit. I just need to see the sine and keep it from clipping when testing amps. I plan on buying software to do the other things I need like THD+N, IMD, SNR, Channel sep, etc.


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