8 Channel, 3U NEVE 1073 completed

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Hey there ! I'm working on a variation of this project and wanted to do the modification of the Decoupling & Output capacitor value increase as well.
Could anyone guide me as to which were the original values and to what they were increased to?

Is there any further adjustment that's gonna be needed if I increase those capacitor values?

Thank you !
 
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>> Why is -- R6 -- shown as being a capacitor? Is this an "OOPS"??? Or, some kind of "secret MOJO" modification???.....

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Silly question, when measuring the transistors for voltages , where do I connect the other probe? ( chassis or audio ground? )

Thank you
 
I run into some issues with sound passing but very low level and distorted. I have to max out the gain to even get a bit of signal
I've tried reflowing all solder joints and checked values / cap orientation for any obvious mistakes but everything seems to be correct.
2N3055 biased to 22.66V

I've taken some measurements from the transistors and it seems that 2 transistors don't match the reference measurements in the guide.
I've replaced TR4 to see if it would make a difference but still get the same readings.

Screen Shot 2024-12-19 at 10.19.38 AM.png

Any suggestions on how to methodically troubleshoot the unit so I can pin point the issue?

Thank you!
 
I just realized I've ordered a 1/4 270R resistor when the BOM states it should be 1W , is there going to be an issue if I keep the 1/4w? The only ones I could find in 1W are carbon film but I'm not sure if it might increase noise/distortion ( never used them before and I keep reading about how noisy they are )

Thank you
 
I just realized I've ordered a 1/4 270R resistor when the BOM states it should be 1W , is there going to be an issue if I keep the 1/4w? The only ones I could find in 1W are carbon film but I'm not sure if it might increase noise/distortion ( never used them before and I keep reading about how noisy they are )

Thank you
I just checked Mouser, and they have several 1W 270R in metal film, from Yageo, TE, and Vishay. I wouldn’t use 1/4W where a 1W is specified.
 
I just checked Mouser, and they have several 1W 270R in metal film, from Yageo, TE, and Vishay. I wouldn’t use 1/4W where a 1W is specified.
Appreciate the feedback! Do you think if I use carbon film , there is going to be a difference in noise? It's gonna be a bit expensive to order just 1 resistor from mouser

Thank you!
 
I just realized I've ordered a 1/4 270R resistor when the BOM states it should be 1W , is there going to be an issue if I keep the 1/4w?

If the BOM says "1W" then that's exactly what you should use, the BOM exists to you don't have to second guess, you just have to follow it.
If you start changing components from the specs in the BOM at you own will then it's normal in the end that you don't have the proper voltages or have problems in your build

Appreciate the feedback! Do you think if I use carbon film

For sure, no problems with that.
"Carbon Film" are very good, just "carbon composition" have pretty low specs and many problems

Original Neve cards used Carbon Film

there is going to be a difference in noise?

No.
The difference will not be even measurable with test gear
 
Thank you @Whoops ! I followed the BOM to the t , even went with military resistors for the sake of double checking the values visually !

The 1w somehow slipped through. I'll get the carbon film 1w!

Thanks !
 
Thank you @Whoops ! I followed the BOM to the t , even went with military resistors for the sake of double checking the values visually !

The 1w somehow slipped through. I'll get the carbon film 1w!

Thanks !
[I'll get the carbon film 1w!] -- "Metal-Film" will be even better and there is basically no price difference than that of "Carbon-Film". Metal-Film resistors will have even lower noise.

Carbon-Film: Mouser #: 660-SPR1CT52R271J = $0.32 each


Metal-Film: Mouser #: 594-PR01000102700FA5 = $0.46 each

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I seem to be battling with this project for while.. any help would be INSANELY appreciated .

All my transistor values are extremely close to the build guide reference except TR1 emitter. I get 350mv instead of 0.4v

The unit is working , I get sound and nothing weird seems to be happening. What might be the reason for the TR1 emitter voltage being that low?
I tried reflowing that part of the circuit but nothing changed. Checked all resistor values and capacitor orientation and they seem to be correct

I'm completely lost!
 
All my transistor values are extremely close to the build guide reference except TR1 emitter. I get 350mv instead of 0.4v

0.4v is 400mV, so if you're measuring 350mV it seems to me it's pretty close and in the ballpark.

remember the notes in the transistor voltage chart:

"Notes:
Voltages were measured with the rail adjusted to +24.05VActual voltages may vary from unit to unit, BUT:
Collector should always be most positive
Base voltage should always be .5 to.6V higher than Emitter"
 
My brain was somehow convinced that 400mv was 0.04v ( Multimeter was autoranging , so that didn't help haha)

Too many lead fumes , must go out!
Got a working unit then! :D

Thank you!
 

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