DIY Class A/B Amp The "Wolverine" build thread

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fvzeppelin

fvzeppelin

Member
Joined 2016
fireanimal said:
I just finished some testing on VAS transistors, CCS transistors, and for fun I wanted to see if there were any benefits to using boutique audiophile capacitors at C1 and how nasty a regular old lytic cap ruins the signal.

First up here are my measurements of some VAS transistor Q13 options, I also measured the C3503D and it performed on par with the C3503E in this position.
Some of these transistors are obsolete or can only be sourced in large quantities but for the most part any distortion at this level of measurement is not audible and you would not be able to tell a difference either way.

From Best VAS transistor to worst would be;
1 / C2682Y
2 / C3503E
3 / C3503D * Should be First Choice as it is easy to find *
4 / TTC004


View attachment 1134296

For the CCS Transistors Q7,Q8,Q11 it was basically a wash between A1381E / C3503E and TTC004 / TTA004, so if you have the A1381E/C3503E great use those, if not get the easy to find TTC004/TTA004's. I did not test D Grade of the A1381/C3503 and being that the TTC/TTA are easy to find and have a higher gain I would use those, or for anyone who wants to save your E grades the TTC/TTA is great choice.

Here are the different capacitors I tried and measured for C1.

View attachment 1134298

And Results of those tests

View attachment 1134297

I would not recommend you spend any $$$ on these audiophile caps, not one of them performed better the the Vishay which is the suggested cap on the BOM.

In fact if you want to save money, the BP 47uF cap actually measures the same as the Visahy, and beats all the other caps as well, which was actually a shock to me

View attachment 1134295

Hopefully you guys find this useful and if you have any questions let me know.

Andy
Click to expand...
Always great to see measurements :love: Thank you!
 
fireanimal

fireanimal

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Joined 2008
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C1 is the only cap in the signal path on the wolverine. It measured the same as the film cap so therefore it will sound the same, I measured to give builders options / lower price alternatives if on a budget. Personally Film is the only way to go in that position, but to each their own.
 
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J

JJGB

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Joined 2011
Hi W team, mirror image boards would be nice so you don't have to put other upside down when you want wires in same direction or is there something that prevent it?

Is 2W emitter resistors ok in every case on ef3-4 boards, I do have plenty of 2w panasonic erx 0.47 resistors.
 
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voxxonline

voxxonline

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Joined 2012
I have quietly progressed with my build:
PXL_20230122_203513767.jpg

One mistake I made is the assumption ebay 60/40 solder will be any good. It gave me more trouble than I anticipated. I have almost completely soldered input boards using it- to realise I was making a mistake. Ordered proper quality 100% leaded solder- day and night difference!
I have ordered 2 fewer Schottky diodes- so had to look them up elsewhere. EBay seller (good reviews) had some reasonably priced. Not sure if diodes can be counterfeit/ fake or not.
Another thing/mistake- I ve got a coil of 19 gauge (1mm) , not 18 (1.2mm)- can I use it?
I have speaker protection and a soft start on the order should be with me in February- aiming to test power up around the second week.
Decided to use AVC autoformer volume control from Tribute, Netherlands without a buffer for now. Will see how it is going to perform.
I have never undertaken a build of this complexity before, will probably post close pics of boards before I connect them to the power supply if you don't mind :)
Things are getting exciting!

EDIT: Looks like I can do 18 turns to reach 1.5 uH. The question now is gauge is fine.
 
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fireanimal

fireanimal

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Joined 2008
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JJGB said:
Hi W team, mirror image boards would be nice so you don't have to put other upside down when you want wires in same direction or is there something that prevent it?

Is 2W emitter resistors ok in every case on ef3-4 boards, I do have plenty of 2w panasonic erx 0.47 resistors.
Click to expand...
Mirror image boards would require a new layout and greatly increase the cost of the boards, but yes it would make things a little neater in the end.

I don't see any issue with you using your 2W resistors.
 
G

ghitus

Member
Joined 2017
Nice looking boards! Just one thing: check the direction you soldered r11 and r25 trimpots. If you decide to install the boards parallel to the heatsinks and in a way so that both IPS look towards the same side, you might meet some problems in adjusting those trimpots once the build is done.

Gaetano.
 
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