More PeeCeeBees…

After a bit of waiting for the postman to show up I now have a couple of new projects to look forward to…

As the title alludes to, it’s a preamp in the “PeeCeeBee” series developed by diyaudio user “Shaan” where I’ve previously showed the small power amp design called the V4.

“What’s another discrete preamp” you might ask, but Shaan’s circuits are normally very well thought-out and solidly designed, so that alone makes the design interesting I think. The second thing that makes it interesting is that the “PCB-pre” allows adjustment of the feedback between the preamp stages via a potentiometer that can be front-panel mounted. This means that it is possible to adjust the amount of harmonic distortion the preamp adds which directly affects the sound signature.

Considering how much emphasis I usually place on system synergy I think this will be a good opportunity to put some of those thoughts to the test, because if the system matching doesn’t matter then I should prefer a specific setting regardless of the partnering electronics, right? 🙂

Anyway, even with the best will in the world I will certainly not be the first one to finish building the pre because I am short some parts that I need to order. Also I can see that Neal over at enjon.uk received his boards so far ahead of mine that I can’t really beat him to making a finished amp 😀

Also included in my shipment were a couple of PCBs for the V4H rev. 2 power amplifier. The V4H is the “bigger brother” of the original V4 with two pairs of output devices per side, but otherwise identical in design and topology. I did actually buy the original V4H PCBs and I was starting to working on them around the time when the preamp group buy was announced. However, when I discovered that the design was being updated to v2 I decided to wait a little and get a pair of those boards instead.

Like the original V4, the V4H is built around bipolar transistors for input and VAS stages, and then Exicon/Hitachi lateral MOS-FETs in the output. This is normally something of a “winning recipe” in amp design and I am looking forward to hearing what a “normal” class AB design can deliver compared to the class D offerings from ICEpower and Hypex that I have been getting used to over the last months…

6 Responses to More PeeCeeBees…

  1. Enjon says:

    Thanks for the link!
    I was originally thinking of incorporating your ICEPower integrated board, but I’m just going for a simple build on this now to keep costs down (smaller enclosure etc.). I’ve adapted your Alps volume board to accept standard 16mm pots as well as the RK27, hopefully that should be here next week. I think I’ve got everything else needed to complete it, just waiting on the enclosure from China, they usually arrive within two weeks.

    • theslowdiyer says:

      You’re welcome 🙂 I was a bit jealous seeing you getting your boards while mine were still stuck in a post office in India somewhere, but they got here in the end ;). My (current) plan is to do a simple one-input design because it is honestly all I need these days and the board is “all-in-one” anyway. Need to get a parts order in though, and then I should pretty much have everything else already – if memory serves me and I am able to find which box I put the small transformers in 😀

  2. ksjung88 says:

    I’ve contacted him and am waiting for the PCBs to arrive. Thanks for your post and link. Although I am not gonna put my hands on it right away, it is always pleasing to see the boards get stacked on the shelf. Maybe I am a fake DIYer. Have a nice day !

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