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PeeCeeBee V4H GB

GB UPDATE:

Torvbakkane - 6 PCBs - SHIPPED
Faizal Mansar Alam - 2 MODULES - SHIPPED
J.M.K - 4 PCBs - SHIPPED
prairieboy - 2 PCBs - SHIPPED
nrabbit - 2 PCBs + MOSFETS - SHIPPED
deps - 2 PCBs - SHIPPED
Greg1017 - 2 PCBs + MOSFETS - SHIPPED
CitizenKane - 4 PCBs - SHIPPED
surajspai - 2 PCBs - SHIPPED

Rick G - 4 PCBs - SHIPPING WITH PREAMP
blek stena - 2 PCBs - SHIPPING WITH PREAMP
routhun - 2 PCBs - SHIPPING WITH PREAMP
Pistollero - 2 PCBs + MOSFETS - DELAYED DUE TO TEMPORARY SUSPENSION OF SERVICE. WILL BE CONTACTED VIA PM/email.
RobSoet - 4 PCBs + MOSFETS - SHIPPING INVOICE SENT

I still have a few PCBs. If anyone needs a pair let me know.
 
GB UPDATE:

Torvbakkane - 6 PCBs - SHIPPED
Faizal Mansar Alam - 2 MODULES - SHIPPED
J.M.K - 4 PCBs - SHIPPED
prairieboy - 2 PCBs - SHIPPED
nrabbit - 2 PCBs + MOSFETS - SHIPPED
deps - 2 PCBs - SHIPPED
Greg1017 - 2 PCBs + MOSFETS - SHIPPED
CitizenKane - 4 PCBs - SHIPPED
surajspai - 2 PCBs - SHIPPED
Rick G - 4 PCBs - SHIPPED
blek stena - 2 PCBs - SHIPPED

routhun - 2 PCBs - SHIPPING PAID
apnneto - 2 PCBs - SHIPPING PAID
RobSoet - 4 PCBs + MOSFETS - SHIPPING PAID
Pistollero - 2 PCBs + MOSFETS - DELAYED DUE TO TEMPORARY SUSPENSION OF SERVICE.
 
Hi mj777,
I'll be interested in your results using the C3503 and A1381. Keep us posted.

Regards
Harry

Hi Harry, all good the C3503 and A1381 are working perfectly. The amplifier boards are very easy to adjust and behaves really well. I have power it up all day listening to all kinds of music and it performs really good. Thanks Shaan for a very well designed amplifier

Regards,
Marjohn
 

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Hi Harry, all good the C3503 and A1381 are working perfectly. The amplifier boards are very easy to adjust and behaves really well. I have power it up all day listening to all kinds of music and it performs really good. Thanks Shaan for a very well designed amplifier

Regards,
Marjohn

:worship:

Happy to know you like its sound. :)

Thanks for the update on 3503/1381 from me too. I just got access to a bunch of them from my mosfet supplier. Have to test them out.

:cheers:
 
Hi Shaan, after setting up the amp and testing it with music playing for some hours and compared to my other two power amps my feeling is that the sound is dull, mid (voices) and high frequencies are not so defined, should I try to fix that by trimming the mosfet bias up or down and to what value of mVs? currently they are biased to 215mV.
 
Hi Shaan,
I then received the prints for amplifier V4H that were ordered, thank you.
Regards
Helge

Below is a picture of a previous revision of V4H, which has then been upgraded to the latest version. And plays fantastic, is very happy. Runs on KEF 107 speakers.
Power supply is from SMPS 800VA with ± 55V, all built in dual mono.
An externally hosted image should be here but it was not working when we last tested it.
 
Everything seems to work fine it's just that the sound is dull, muddy, too dark maybe I don't know how else to describe it.

Hi.

The v4h does have its own sound but dull/muddy it is not. So definitely something is going wrong. Turn on the amp and slightly touch the 10ohm resistors near the output and check if they are warm. If not, then the problem may be coming from a faulty transistor or capacitor that is running off its specification. Have you checked VAS bias at the 47ohm resistors? What transistors are you using at VAS?