HiFi Tube Pre-amp: Wiring the Power Supply

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2 жыл бұрын

In this segment I show the fab work + wiring the power supply. This series is less step by step as we just did most of this in the recent spud amp build, and will be more "high level".
This simple circuit has gotten a lot of praise. I'm a fan of simple audio gear so I'm going to throw this together and compare it to the winner of our shoot out, stay tuned!

Пікірлер: 25

@primepreowned1 2 жыл бұрын

Neat job. Can’t wait to build one myself. Thanks 🙏

@themeeksproject9785 Жыл бұрын

now everybody where inspired by you .....thank you

@amimaster Жыл бұрын

Thanks for this video! I'm starting my own adventure in building my dream guitar amp, however not many videos focus on the actual building of power supply (i.e., all that's before the reservoir). Albeit my design is much more complex than this, you confirmed some ideas I had previously, such the use of tag strips, and gave me some insights on what to expect in terms of chassis occupation. In the latest years I've studied A LOT of theory, but seeing how to apply it in practice is invaluable.

@goofysvintageworkshop6728 2 жыл бұрын

Nice video 👍

@jeffkamen2307 2 жыл бұрын

Hey, that 150uf cap looks like it may have once lived in a Nobsound 6P1… 😂

@SkunkieDesignsElectronics 2 жыл бұрын

BUSTED lol

@WoodandSteel 2 жыл бұрын

Can not wait to build one of these. A quick question if you have the time, about the power transformer rating of 75mA. Using two 12at7 with a max 20mA cathode current per tube, leaves a lot of head room. I would like to use a transformer rated at 55mA, that should provide the 40 mA requirement for two tubes. 37% to spare on the transformer rating.

@SkunkieDesignsElectronics 2 жыл бұрын

Yeah, this could easily be built with a smaller power transformer. It's actually only using one tube, so 75ma is way overkill but it's what hammond has that also has a 6.3V for the heaters.

@KUDJU 2 жыл бұрын

If the neutral wire is direcly bolted to the chassis and the star ground point is connected to the chassis isnt there a risk for ground loop appearing ?

@SkunkieDesignsElectronics 2 жыл бұрын

Yes but I've been doing my audio gear like this and never run into it. I would never build tube audio gear with a ground floating that could potentially go live (the outside part of the RCA jacks) and have 200+ volts on it without blowing the fuse.

@BMH-cb9jt Жыл бұрын

Im looking to make a external pre amp for a guitar amp. Im wanting to run duel 12AX7 would you happen to have a layout diagram i could possibly use for this?

@SkunkieDesignsElectronics Жыл бұрын

I haven't gotten into guitar amps yet. That is a whole different world!

@subzerothought Жыл бұрын

I built the 4s preamp and it worked great for about a year then 1 day I turned it on and sat down to.listen then suddenly see smoke coming from the transformer. It was hot in the room and I had the amp on a shelf where heat could build up so I figured that was the problem. I replaced the transformer and the same thing happen again and temperature was not a factor. Could it be a bad tube causing this? Any clues as to what could case this?

@SkunkieDesignsElectronics Жыл бұрын

More likely there is a short, it could be a shorted tube? Also the fuse should have blown I would have thought.

@subzerothought Жыл бұрын

@@SkunkieDesignsElectronics The fuse did blow but not before the Transformer started to smoke. I kind of leaped across the room to turn it off but the fuse must have blown just before I did. I will check the tube for shorts. I should have used the bulb and Variac when I hooked up the second transformer but I just assumed it was a bad transformer. Lesson learned. One thing I noticed was that it seemed as if the rectifier tube was glowing brighter than normal? I appreciate you taking the time to reply. Love your content! I built the 300B and LOVE IT!

@subzerothought Жыл бұрын

@@SkunkieDesignsElectronics Found that the rectifier heater is shorted to the cathode! Thanks! 🤓

@SkunkieDesignsElectronics Жыл бұрын

Glad you found the problem!

@wesleymatthews137 Жыл бұрын

In your schematic for this power supply, the 33uF Cap is 450v and the 150uF Cap is 350v. In the install, it’s the opposite. Which one is incorrect? Or, maybe 350v is plenty here anyway?

@SkunkieDesignsElectronics Жыл бұрын

350V is plenty regardless of position. I'm not sure on this project if I posted "my schematic" or the one from the guy who designed this.

@TheMirceanedelea 2 ай бұрын

hi! sorry to bother you again with my questions but i would like to find a power transformer to use in europe. thank you in advance

@SkunkieDesignsElectronics 2 ай бұрын

I gave you the link in a previous comment, THERE ARE USABLE IN EUROPE VERSIONS for all these hammond transformers. The 300 series has primary windings for 100V, 110V,120V, 220V 230V 240V. Just look up the part number with a 3 instead of a 2 i.e. instead of a 274BX, look up a 374BX.

@TheMirceanedelea 2 ай бұрын

@@SkunkieDesignsElectronics, thanks a lot