My latest project - KT88 SE tube amp

[PWR RYD]

After seeing Bryan's pictures from the Chicago audio show this weekend I thought there might be a little more interest in tube amps. Previously I have built a line stage 6DJ8 preamp, a pair of KT88 push-pull mono blocks, and a small push-pull amp for my office at work. This project is my first single ended tube amp. It will be all tubes, ie. no semiconductors. The circuit is based on a project/kit that a cool guy named Scott was selling on diyaudio. Here are a few pictures of the early stages of the case:







The wood is maple. I plan on shellacing it with Zinnser's amber shellac so it looks like the neck on my Fender Strat.

[TN Allen]

Re: My latest project - KT88 SE tube amp

It's great to see a tube amp project on the forum, I'm looking forward to following your progress.

[Whitneyville1]

Re: My latest project - KT88 SE tube amp

Here I wanted to see pics of burned finger tips and rat's nests of wiring! I like the 35 pound "clamp". Toob amps can have a nice sound to them. Direct coupling eliminates the gigabuck output transformers that normally make so much difference in the sound. Have fun Craig. I like your cases, they should come out nice. I'm a fool for bird's eye or flame maple (cha-ching!) veneer down at the hardwood store, but I like your's too. Careful of the 380-450 V B+...it makes you see funny for a while...;)

[mikejennens]

Re: My latest project - KT88 SE tube amp

Lookin' good Craig. Gonna bring that to the next DIY Iowa? I saw that on DIY Audio. Pretty good deal.
Mike

[OlderMongrel]

Re: My latest project - KT88 SE tube amp

Nice! How much power will you likely get from this? Any plans on other components to use with it?

John

[PWR RYD]

Re: My latest project - KT88 SE tube amp

I'm building this amp to drive the Stances sitting on the shelf over my basement workbench. Right now they are powered by a Sony boombox :o This single ended design should produce 10 clean watts per channel in UL mode. There will be a switch so I can change between UL mode and triode mode.

Mike I certainly can bring it to Iowa next year if you want to hear it. The kits Scott was selling were actually a really good deal at ~$800 but piecing it together myself and building the case I will only have about $300 total invested. I skimped a bit and went with Edcor's GXSE 15 Watt output transformers instead of the huge CXSE 25 Watt iron. I can always upgrade in the future if need be.

Project update: I applied 2 coats of the amber shellac last night. I'm really not happy with the color so tonight they get sanded back to bare wood. I'm going to try clear shellac and see if I like the blonde look better

[Æ]

Re: My latest project - KT88 SE tube amp

After seeing Bryan's pictures from the Chicago audio show this weekend I thought there might be a little more interest in tube amps. Previously I have built a line stage 6DJ8 preamp, a pair of KT88 push-pull mono blocks, and a small push-pull amp for my office at work. This project is my first single ended tube amp. It will be all tubes, ie. no semiconductors. The circuit is based on a project/kit that a cool guy named Scott was selling on diyaudio. Here are a few pictures of the early stages of the case:

Hey, you're not the only person around here to have built a tube amp.

[fezzywigger]

Re: My latest project - KT88 SE tube amp

Ive built a couple of those k-12 tube amps, i really like them. My current one it still just mounted to a board, I really got a fashion up a case for it do I am very happy to see this thread!

[PWR RYD]

Re: My latest project - KT88 SE tube amp

Awsome looking amp AE! Much nicer looking than my K-12:



Tubes are such a natural type of DIY project (wood cases and point to point wiring) I'm surprised not to see more of those posted here.

[evilskillit]

Re: My latest project - KT88 SE tube amp

How much does it cost to pull together one of those k-12 projects out of curiosity?

[PWR RYD]

Re: My latest project - KT88 SE tube amp

$199 plus a few small items like a power switch, fuse holder, etc. Here is a link:

http://www.tubedepot.com/diy-k12g.html

[mikejennens]

Re: My latest project - KT88 SE tube amp

https://id3466.securedata.net/s5elec...tubeorder.html

There are a few different amps available through this site.
Mike

[evilskillit]

Re: My latest project - KT88 SE tube amp

$200 give or take isn't awful, but if you shop hard there's a lot of good second hand gear, or even new gear out there for that or less and that probably has something to do with it. I do want to DIY an amp some day, maybe a bunch of them but when I'm poor and I need amplification I just keep trolling e-bay and craigslist.

When I do make an amp I'll probably start with a gainclone and see what all that fuss is about.

[mikejennens]

Re: My latest project - KT88 SE tube amp

$200 give or take isn't awful, but if you shop hard there's a lot of good second hand gear, or even new gear out there for that or less and that probably has something to do with it. I do want to DIY an amp some day, maybe a bunch of them but when I'm poor and I need amplification I just keep trolling e-bay and craigslist.

When I do make an amp I'll probably start with a gainclone and see what all that fuss is about.

One of my first DIY amps was a rebuild of a Packard Bell tube amp, circa 1963. There was a LOT of help from the DIY Audio forum. I paid $25 for the PB console at a thrift store, gutted it, threw away most of it, and spent less than $75 on parts to rebuild it; mostly caps. The wood to make the frame was some scrap I had lying around. It turned out very well and I recently sold it for $100. It was pretty much a break even deal for me, plus it was fun and pretty cool. I also built a Peter Daniel Audiosector amp which is nice, a Velleman amp from PE which was OK, and a Chinese amp I got off eBay which never did work. When you're in the position to get one, you'll probably have a lot of fun with it.
Mike

[bkeane1259]

Re: My latest project - KT88 SE tube amp

Hey, you're not the only person around here to have built a tube amp.

Wow...that's beautiful, Alan. Great job. I'd love one of those on my desk.