Finished my First Tube Project!

[todd.brust 29]

Well I just finished my Heathkit AA-151. My first tube project. I had a thread going over at ForceAudio with all the progress and pictures but the site is currently down. I'll get some pictures up in a bit.

I finished mounting the RCA Jacks today, which was all that was left of this project. Prior to today I have replaced the PS caps, coupling caps, and any electrolytic capacitor. I also changed any out of tolerance resistors, and I eliminated the Xtal Phono input and replaced to according input resistors to make an additional auxiliary input. All the input Rs were also replaced. I was planning to go through and replace all the components in the RIAA Eq with 1-5% tolerance parts, however I became to anxious and just ended up skipping that for the time being. I still have yet to listen to anything on my record player. But I have a slight problem. The volume knobs are scratch when turned and i don't know what to use to clean the Pots. Any suggestions would be appreciated. I was told there is some product at radioshack but i forget.

So far I tested the amp on a small set of Zenith surround sound speakers. LOL. They are only thing I have laying around at school now. The audio input was from a PC running off Slacker internet radio. Not the best first impression but everything did sound very good . Hopefully I can get some time to hook it up to my Scott S-10s at home tonight and listen to some vinyls and get a better idea of the sound. Won't Get Fooled Again by the Who came on and was pumped. I started to mess around with some of the controls. One thing i noticed that the Heathkit did especially well is imaging. I was more than impressed with that.

Enough of me blabbing though here are a few pictures.

[todd.brust 29]

How it came

This is what was fixed today.

Top side

I hate Point to Point wiring!!!!

[todd.brust 29]

I decided to have the case sandblasted and painted. (Note to everyone. Never try to sandblast a Heathkit with the orange fake vinyl covering. That case alone took at least 10 hours to get fully sandblasted. The stuff is thick!)

The dial piece still needs to be sandblasted and painted. That is going to be painted to look like brushed aluminum. And the Chrome brow piece is going to get polished.

I don't have any pictures of what was replaced and whatnot, but you get the idea, different caps and resistors.

Edited April 11, 2008 by todd.brust

[topgun 262]

Ohhhh, tubes.

Looks good.

[Acidburn 10]

good ol' Heathkit

my Dad made some of their stuff back in the 70s

[johnecon2001 82]

Contact cleaner will clean the pots up.

[todd.brust 29]

I was told to avoid certain contact cleaners. Is there a specific type you would suggest or would any contact cleaner work?

[X-OvrDistortion 0]

I remember when you got that, it is looking better bud.

For cleaning the pot, you can use alcohol and a qtip too.

[JimJ 11]

I've had good luck with Caig DeOxit.

Looks good

And it's either P2P wiring or dealing with PCB traces, and I'd take point to point any day over that

[todd.brust 29]

Sounds good... Thanks Guys

The more I listen the more I like it. It sounds great on the Scotts. Really smooth bass and the sound isn't even the least bit harsh. This is the first tube amp I have ever heard.

Only problem now is that when it gets warm, it starts to smell. Not the amp but that paint I think. It is suppose to be a high temp paint but after a half hour of use it just starts to get kind of strong. I may end up running it without its cover.

[///M5 2,833]

Bummer since the paint looks nice too. Perhaps it will mellow out after a while, perhaps heat it up a bit with something else to evaporate the volatiles.

[todd.brust 29]

yeah that's be nice...when it gets nice out i'll just open with windows and run it and see if it slowly goes away.

The inside is painted with a high temperature paint but not the outside.

It does look sharp though. My buddy mixed it for me at his work. It has pearls mixed in so when you look at it under the sun or any bright light it just shines. I planned on getting the front piece with the dials painted to look like brushed aluminum but it i'm not going to have a cover there isn't a point to doing it

[JimJ 11]

Heck, I don't know how much you want to throw into this, but a DACT stepped attenuator would probably blow the original pots out of the water

Or at least a good quality ALPS or Noble stereo pot...

[todd.brust 29]

Those DACT pots are nice, but probably cost me more than I NEED to spend. But they also well the aluminum knobs to go with them and that'd be great if i ever get the front painted! Argh. I looked for a noble but they don't come in a 1Meg from what I saw.

Oh well I can't throw too much money into this project. Now that I have one done, I want to do another! Maybe a SET. I need to start going to garage sales and see what treasures I can pick up.

[Aaron Clinton 2,372]

The paint is very attractive.

[todd.brust 29]

The smell is getting less intense the more I use it. The guy who painted it for me said it is curing the paint more and it should gradually go away. I swear I got high just sitting in my room with the amp yesterday! I may just take it into the garage and run it for a few hours and hope the paint cures!

But I do love the sound of it!

[JimJ 11]

When I first fired up the SV811's, my apartment reeked of polyurethane for a week straight because I didn't realize how much heat the things would produce

[todd.brust 29]

Yeah I think I am going to remove the cover and just run it like that for the time being. I am getting dumb sitting next to the thing! LOL A buddy from work has an idea or two so it won't heat up as much. Let's hope it works. I still need to get some pictures of the assemble amp too!