Hi fellows.
So last couple of weeks have been busy tweaking the V4H for best sound quality and stability. While the amp is stable nonetheless, it took more time than I expected to reach an optimum setting for the best sound. After many soldering sessions and hours-long listenings the amplifier has been finalized, with much better THD vs frequency than V4 as mentioned before. The excellent LF performance of V4 remains unchanged in V4H, but mid and higher octaves are now much more balanced. Overall V4H shows both measurable and perceptible improvement in overall music presentation than V4. The sonics have been "refined", to express in the "audiophile" sense.
The final board has been re-touched to be 5mm larger than the prototypes in width. Speaker output now stands near board edge, meaning PGND to SGND connection no longer crosses speaker output cable. Didn't notice any behavioral difference in the amp due to this but it sure makes wiring simpler and looks better as well.
MOSFETs don't need to be matched, as we will be using source resistors. Those who can procure matched MOSFETs just need to use wire links instead of the resistors, i.e. short them.
V4 Rev 2 ?... I am excited...
Yes!
For existing owners of V4 Rev1. No. (for a good reason)
The main changes in V4 Rev2 are better placement of the MOSFET and VAS transistor mounting holes which will allow easier placing of ECX MOSFETs as well as the 2S pair, along with a little more leg-space for the VAS pair.
Note that Rev2 will also use the same mod that improved V4H's THD performance and will have accommodation for the necessary extra components. All future GB members for single MOSFET pair V4 will receive Rev2 boards.
(the good reason)
Can the existing V4 Rev1 owners use the mods on their own boards to improve performance? Yes! All will be shared here as soon as V4H GB goes online.
Hi Shaan,
This is my V4 board +/-24VDC rails with ECX MOSFET under testing. According to your instruction manual, it is very stable and well control in DC offset (within few Vm) and able to bias upto 600mA value. After 30 minutes, heat sink tempature up to 45 degree (in room tempature 20 degree).
Finally I adjust the bias current back to 300mA due to overheat on my bit small size heatsink.
This is my V4 board +/-24VDC rails with ECX MOSFET under testing. According to your instruction manual, it is very stable and well control in DC offset (within few Vm) and able to bias upto 600mA value. After 30 minutes, heat sink tempature up to 45 degree (in room tempature 20 degree).
Finally I adjust the bias current back to 300mA due to overheat on my bit small size heatsink.
Attachments
O.k. ?! It seems there is the need of an update to the BasicInputOutputSystem from PeeCeeBee to Shaan 2.0
It's more like a hotfix for V4 Rev1 than something radical like a BIOS upgrade.
So the actual shipping is Rev. 1, right?
Nope. Rev 2.
Have you tried to keep the heatsinks in a vertically oriented fin position i.e. standing up instead of lying down? From its apparent size it seems to me that it should be able to take the extra dissipation well if placed vertically.
We are heading towards it now. V4 GB4 will roll as soon as we reach 40 PCBs.
craydive - 6 PCBs + 12 MOSFETs
hajj - 2 PCBs
Medisinmannen - 2 PCBs
Surfatwork - 2 PCBs
Hi Shaan,We are heading towards it now. V4 GB4 will roll as soon as we reach 40 PCBs.
craydive - 6 PCBs + 12 MOSFETs
hajj - 2 PCBs
Medisinmannen - 2 PCBs
Surfatwork - 2 PCBs
Is GB4 for V4 Rev 2? Is there a BOM so that I check the parts availablity.
Regards
Bilal
Hi Keesraats!
It's an honor to know you chose PeeCeeBee V4 as your first DIY amplifier!
Welcome to the diyAudio forum, it's fun here.
Thanks Staan. Alsof nice day's for you. I now see my autocorrect made a mess of my text. I am interested a long time but never had the guts to really make one myself.and this amp looks to me very interesting. I would like to order 2 pcb's. Any idea when the pcb's are send out. I'm eager to start.
nice days from Holland.