Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Misc Schematics and Layouts => Topic started by: blackcorvo on September 14, 2023, 01:28:32 pm
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I've been working on an amp inspired by the Supro 1606 / (but using two PCL82 tubes), and recently I haven't had the space to keep working on it at home. However, I had some free time at work, so I drew up the original amp's layout on DIY Layout Creator to pass the time, and because there's no drawn version of it anywhere.
I've also compiled all the reference pictures I've found into a Google Drive folder for anyone to view, as wellas the DIYLC file:
https://drive.google.com/drive/folders/1TgIn41hioDNH7-CvfoIGfYPfNP6IvQ3O (https://drive.google.com/drive/folders/1TgIn41hioDNH7-CvfoIGfYPfNP6IvQ3O)
You may notice there's 2 variants of this amp: one sporting an indicator light and panel mounted fuse holder, and one without the indicator and with an internal fuse holder.
I chose to base the layout on the latter, as I feel it covers the more relevant parts of the amp.
Of course, there are modern improvements we can do to make the amp as noise-free and reliable as possible, like a grounded power cable, twisting the AC lines, and using resistors to make a center-tap on the 6v AC wiring, but I think having a representation of the original amp online is a valuable tool to have.
[EDIT] fixed missing P.T. ground wire.
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You're missing a very important wire for the power transformer. There should be a red/yellow wire that connects to chassis. Some of your pics show this wire connected to a ground lug on the 6V6 socket. Your schematic does not show this wire connected to ground either. This is not an optional wire. It must be connected to ground.
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You're missing a very important wire for the power transformer. There should be a red/yellow wire that connects to chassis. Some of your pics show this wire connected to a ground lug on the 6V6 socket. Your schematic does not show this wire connected to ground either. This is not an optional wire. It must be connected to ground.
Thank you very much! I'll rectify that error right away.
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And here's what I am calling my "modernized" take on the amp, with some changes to bring it up to modern safety standards and building practicies (twisting AC lines to reduce hum, adding resistors to the 6v line to give it a "center tap", grounded power wire, shielded cables on all signal wires, etc), while keeping the majority of the layout very similar.
I also added Jeff Bober's (https://www.premierguitar.com/gear/reviews/ask-amp-man-if-it-aint-broke-dont-break-it) mod, but it's totally optional.
[EDIT] Fixed misplaced resistor lead.
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V1 pin 2 no longer has a resistor to ground.
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V1 pin 2 no longer has a resistor to ground.
Thank you. THIS is why I post here, I sometimes don't catch obvious errors like that. Corrected.
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I wanted to build a 1606 Supro Super, but with an eyelet board like fender instead of point to point component to component. Has anyone on here transcribed a super diagram to an eyelet diagram?
Thanks
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The 1606 is the same as the 6606 except the 1606 has no tone control. Here's a 6606 layout (https://sluckeyamps.com/misc/Supro_s6606.pdf).
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The 1606 is the same as the 6606 except the 1606 has no tone control. Here's a 6606 layout (https://sluckeyamps.com/misc/Supro_s6606.pdf).
Thank you! I hadn't seen it till now so I i ended up prototyping my own layout for now.
I know that it's been a while, but I've decided to get back on this project. I've wanted to try making an eylet board build for ages, and this is the result so far:
i=fRfKigcDlnzyoaPe
If I do use an eyelet board in the final build, I'll definitely try something more substantial than a random cut off a cardboard box hahaha!
I'm now just struggling with the balance between B+ (currently 147.5v) and output stage operating point. I want to get as close as possible to the 6W output the original 1606 amp could provide, but it seems it'd require more B+ voltage (170v), but then if I make a voltage tripler to get it, the B+ goes over 200v without load, which is above what my quad-capacitor can handle, and I'd like to keep it in the project because it looks cool, and allows me to make my eyelet board smaller.
That's about it, see you on the next update.
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Last update on the schematic. Did some changes for better response (IMO) to suit the PCL82's triodes.
(https://cdn.bsky.app/img/feed_fullsize/plain/did:plc:5i7f5z5b5ppxyk6ikrpup4gc/bafkreia27h4zqmqdnu5xsreobevb6xab2iup7mkdv6hycfr2wjh4dw3jsi@jpeg) (https://cdn.bsky.app/img/feed_fullsize/plain/did:plc:5i7f5z5b5ppxyk6ikrpup4gc/bafkreia27h4zqmqdnu5xsreobevb6xab2iup7mkdv6hycfr2wjh4dw3jsi@jpeg)
Also used a 32v+32v P.T. to actually get around 150V B+.
Sound sample: