PEECEEBEE V5 GB

[gary s]

Yes shaan , I hope you are back to full health soon - that always has priority.

 

[shaan]

The board is damaged and I have to make a new one. The problem was that was not increasing bias... I changed everything but nothing happened. The offset reset normally and the only difference in the measurements with the other board was that r31 r31 had 1.7k...... in the good only 0.2k. I also can't measure mV in the resistances you give in the instructions. I will need a new board immediately...

Correct me if I am wrong. R31 measured 1.7K while its marking bands read 220R (Red Red Black Black)? If yes it would be very odd. Generally metal film resistors do not get made that much outside their marked value. The R31/32 will not get in the way of changing the offset but with such a high value it should cause VAS bias related issues which I think happened in your case.

I do have some boards left. I will PM you shortly.

 

[Prodigy85]

Finished 1 channel. Will do the 2nd one now and share the final results.

 

[nanakos]

I have mentioned that I did not manage to measure mv on the 32 resistor, so I put the multimeter in series to the positive and increased the bias to 200 mA because my power supply is only 42.5V. The hot was very little...

 

[Prodigy85]

Finally got the amp singing.
@shaan .. it’s beautiful. Thank you 🙏

Will wait for the break in now.

Regards,
Som

 

[Vunce]

Beautiful looking V5, Som!
Can you post a pic of the inside?
Linear or SMPS?

 

[nanakos]

Shaan on the problematic board while the offset is 0 I cannot increase the bias. What could be wrong? I have changed all the drivers

 

[nanakos]

Finally, the amplifier sings perfectly!!! If you ask me which of the two is better, I honestly don't know... the rev5 is very good, but the rev4 is also fantastic. However, it is too early to judge yet.

 

[bullittstang]

@nanakos What was the issue? Might help other builds trouble-shoot their problems.

 

[Oracle1]

Nanakos, about the heatsink, what did you choose?

 

[nanakos]

@nanakos What was the issue? Might help other builds trouble-shoot their problems.

I changed all the 5551 and the problem was solved

 

[nanakos]

I used the same heatsinks with rev4 but the heat is less here

 

[Prodigy85]

Beautiful looking V5, Som!
Can you post a pic of the inside?
Linear or SMPS?

Thanks @Vunce . I’ll post the internal pics soon. Been busy with work but l did make some time to give it a serious listen and the amp is simply fantastic. From the day 1 to day 2 the amp is settling down quite nicely and I think another couple of more hours and should be able to hear the best out of these. Getting more musical 🎵

Waiting for the next GB from Ostripper for spooky and hell raiser 😀

 

[redjr]

@shaan Have all the PCBs for the current V5 GB been mailed out? I'm still waiting for mine. Just checking on the status. Thx.

 

[Vunce]

I changed all the 5551 and the problem was solved

Were the 5551's that were removed from amp purchased from a reputable supplier? (Mouser, DK, RS, etc..)

 

[nanakos]

they are all from the same series from mouser

 

[nanakos]

After two days the.bass came to life...very strong and punchy.
Much better than rev4.
Highs soft sweet and crystal clear.
Middle frequencies are a little behind and not at all aggressive. And in this area better... than the already excellent rev4

 

[nanakos]

Bias at 300mA and!!!
OMG
Sound from another planet....

Shaan this time exceeded all expectations

 

[nanakos]

Nanakos, about the heatsink, what did you choose?

large...4kgr per channel...rev4 was ok with these.
Simply changed the boards...

 

[Prodigy85]

View attachment 1183114


View attachment 1183115

Bias at 300mA and!!!
OMG
Sound from another planet....

Shaan this time exceeded all expectations

Keen to know what was the difference like. I have currently biased it to 150ma like Shaan suggested in his build guide. Will bump it up over the weekend. I have big heat sinks too so heat should not be problem.