Tube amp kits

[riverrat373]

I would like to build a simple tube amp kit and have been looking at the K-12M and the K-502 kits. Does anyone have any experience with either of these kits? Which one is the better amp? I know that both can be modified for better performance, but is one easier to modify than the other?

Thanks,
riverrat373 Yellow_Light_Colorz_PDT_14

[hembrook]

It was easy to buld and I did some of the mods from Voltsecond's site. But honestly it sits neglected as I have built some other things. It is a 120V amp in a 240V world over here in Germany.

[RuralUrban]

I built a pair of the K501mono amps, I upgraded the power supplies, added several of the voltsecond mods, added individual catohode bias ala Shannons ST-35 circuits, and used Hammond 1609 OT's. The results are fantastic, but with all the mods, I ended up $50-$75 less than a DIY st-35, which I also built and like better, but make no doubt, the little K unit sounds great, and if it was all I could've ever done with a tube amp, I would have been happy. As it turned out however, was only the beginning of an incurable affliction.

The new S-5 units however, using the 6AQ5's, besides the iron, they are so similar to the Dynaco circuit and with their pricing, I would definitely just save a bit more cash and get a DIY ST-35.

If You search on these amps You'll find this mentioned, but the K502 (from AES) at one point, (I learned all this from You guys at DIYTube) used 11BM8 tubes, while all the other variations (K-12, K11, and even K501) used 11MS8/10GV8 tubes. To make a long story short, the only one that really takes kindly to Ultralinear operation (with upgraded OT's) is the K502...For whatever reason, the other variations (like my K501 mono's) just do not work so well with this modification. I think this is the only meaningful difference one needs to know with these original G.F. designs. Those that have modded their K502's (11BM8) for UL operation, report back that they are pleased, As I am with my version (11MS8) running pentode.
I recommend these kits, If it's all You can ever afford, You'll be happy, or, like me, You'll still be happy, AND want more.

[TomMcNally]

Mr. Rat ...

If I were you - I'd start with one of the diytube ST-35's ...
the circuit board and instructions are of great quality.
The support here is excellent - and the amp sounds great.

You could buy a premade chassis, or save a few bucks and
make your own, or use a Hammond.

Why start with a compromise and try to make it into something,
start with something that has quality !

Here are some of my amps to look at: http://tmamps.com

... tom

[riverrat373]

Thanks for the replies on my question of which amp kit to buy! I ordered a K-502 kit from Antique Electronic Supply and am excited about building my first tube amp! I plan to mount it on a metal chassis that I also purchased from Antique Electronic Supply and trim it out with solid oak. I will post a photo on the forum when it is finished. Yellow_Light_Colorz_PDT_12