Author Topic: pix of Custom built guitar amps/cabs  (Read 316683 times)

Marcos - Munky

Re: pix of Custom built guitar amps/cabs
« Reply #860 on: December 03, 2019, 07:07:25 AM »
In my experience, there's a few things that matters.

When I was testing this one outside of the enclosure, the boards position matters. I mean, when the tda board was closer to the 555 smps, it was noisy. But when everything was mounted in the enclosure, the smps and tda boards ended up very close to each other - but with the enclosure as a ground plane between them - and I got no noise at all.

If you're building the smps, a good layout helps to low the noise level. I once built a alembic tube pre with a (bad layout) integrated smps, the B+ tracks were at wrong places too near the signal tracks, and I got some high frequency bleeding. After that bad experience, I drew a layout for just the smps and use it as a separate board. I've powered a few circuits (alembic preamp, jcm preamp, fender twin-like preamp, ef184 preamp, mesa boogie preamp, ecl84 amp, 6n16b submini tube amp) using it and got great results.

If you're using a already built smps, you have to give it a try. Some of them are not made for audio and can be noisy (I have a dc step up board that's way noisy), while others aren't noisy at all.

The "main" power supply matters too. A noisy power supply without some good filtering will put noise in the circuit. This noise will go thru dc converters and can get noisier if there's no filtering. That said, some power supplies we suppose it's noise may give good results. I've powered a mesa boogie tube preamp using a sony psp power supply with no noise at all :icon_twisted:.

Your idea is very doable. I'd say to give it a try. Use a tested layout for the preamp (if you have one) and, if you're building the smps, use a tested layout too. I can send you the one I use if you want. If you're using a dc converter board for the smps, you'll have to test it to check for noise levels. Play around the board positions (maybe add a ground shielding around the smps if the boards end up closer to each other and you get noise bleeding) and the B+ wire, and keep in mind it'll probably sounds noisier outside the enclosure than inside of it, and you're good.

Btw, does this tube mic use transformers or not? So metimes I think on building me a tube mic preamp, but the transformers keep the idea out of my building list.

rankot

Re: pix of Custom built guitar amps/cabs
« Reply #861 on: December 03, 2019, 09:05:13 AM »
Actually, it is so called Shroom mic preamp (by Fred Nachbaur), transformerles indeed, but I changed it to use EF86 and 12A*7/6N2P. I still didn't build it, but I can open a new topic about it if your're interested. Already did a PCB design, but it could be better if someone could take a look at it before I start soldering :)
Ampegulator, Bassballs, Bazz Fuss, Bearhug Compressor, Bronx Cheer, Clean Sweep, Demeter Compulator, Electra Distortion, Engineer's Thumb, Hybrid Fuzz, Orange Squeezer, ProCo Rat, Ross Compressor, Valvecaster, 6J6, SFT 2, Ugly Face, more to come...

Marcos - Munky

Re: pix of Custom built guitar amps/cabs
« Reply #862 on: December 03, 2019, 11:25:35 AM »
I did a little research on it and found the schematic. Looks interesting. The thing is it uses 2 pentodes, which I'm out of them rn and tubes are somewhat hard to get here, so I can't add it to my projects list (at least for now). But I can take a look at the layout if you want.

Btw, for 220V out of that smps, a small heatsink may be necessary.

rankot

Re: pix of Custom built guitar amps/cabs
« Reply #863 on: December 03, 2019, 12:41:36 PM »
Ampegulator, Bassballs, Bazz Fuss, Bearhug Compressor, Bronx Cheer, Clean Sweep, Demeter Compulator, Electra Distortion, Engineer's Thumb, Hybrid Fuzz, Orange Squeezer, ProCo Rat, Ross Compressor, Valvecaster, 6J6, SFT 2, Ugly Face, more to come...