New Member- got some questions

[caveing]

Hello there amp garage. I've only recently found this forum and I've been reading it quite a bit. Just decided to join because I've been getting into amp building after several years of building pedals and modding amps and whatnot. I've got a couple projects ongoing right now that I could really use some help with.

I've got a fender pro reverb that needs some love (even though I've loved the crap out of it recently with tons of new components). This is the most pressing issue, but I'll make another thread for it.

I'm working on planning a Dr Z build- I'd like to do the z28, but cant find a layout- I do have a Stang Ray layout though... might do that.

And I also received an AmpMaker double six kit for christmas from a relative. Looks like a cool amp- I built it up and tested it, but burnt out a resistor on start up. Put it aside for a while and emailed Barry at Ampmaker. He gave me some suggestions and told me take pictures to send to him, I put it aside for a couple months and then tried to get back to him with no avail. He hasnt answered me in 2 months. Since that time my cat absolutely destroyed my component list that puts values to the parts on the layout! Unforuntately this document is not available on his site. I thought someone around here might know. I cant double check my layout now! Sucks! If anyone could help me out with that I would be very grateful.

Anyways- I love the look of this forum and all the awesome stuff you guys do. Can't wait to dig around here some more and get more into the things that make amps tick!

[surfsup]

Post some detailed pics, anyway. If a component is totally off, this group will catch it. Probably a wiring issue. Can't help you without pics or more description. Do you have a DMM? did you ever take voltage readings?

[Tillydog]

And I also received an AmpMaker double six kit for christmas from a relative. Looks like a cool amp- I built it up and tested it, but burnt out a resistor on start up. Put it aside for a while and emailed Barry at Ampmaker. He gave me some suggestions and told me take pictures to send to him, I put it aside for a couple months and then tried to get back to him with no avail. He hasnt answered me in 2 months. Since that time my cat absolutely destroyed my component list that puts values to the parts on the layout! Unforuntately this document is not available on his site. I thought someone around here might know. I cant double check my layout now! Sucks! If anyone could help me out with that I would be very grateful.

I believe Barry is in the process of moving premises and somewhat busy at the moment.

I played through a Double 6 a few weeks ago - it was a bit too clean for me .

The instructions for the Double 6 are on the shop page for the amp which is currently disabled as he stopped taking orders for a while . There is a build guide for the double six on his site, though:

http://www.ampmaker.com/infocentre/forum-29.html

From the links within the above:

Schematic with component values:

[img1458]http://www.ampmaker.com/images/ak02kit/ak02sc2.jpg[/img]

Turret board layout:

[img519]http://www.ampmaker.com/images/ak02kit/ak02cw9b.jpg[/img]


There are also sections on wiring, etc. and the startup guide.

As Surfsup said, if you tell us what you've done so far & put up some good, clear, high resolution photos, I'm sure your problem will be sorted quick-smart.


Andy

[caveing]

Thanks a bunch! Yeh I figured I would post pics and whatnot after I did a little testing of my own. I borrowed some components from the amp as it sat and I had some work to do on other projects, so I'm gonna reinstall those and recheck everything.

I do have a DMM and did all the continuity testing. When i powered on I didnt do the initial voltage tests because I burnt up R28- the 1k3W resistor between the filter caps and the power tubes... One that you'd find in the filter can of fender amps... (dont fender blackfaces only use 1w resistors here?)

Barry hasnt sent me anything in months, which is ridic... but he did answer me intially a while back and I just didnt have time to work on it immediately after. Anyways, he thought the power transformer could be bad for some reason and was supposed to send me instructions to check the transformer's health. I guess that info would be good to have if it's around, I was under the impression that power had to be on to check the transformer or you had to have some special tools.

Thanks a bunch for pointing out the schematic's indication of component cross references! Can't believe I missed that... always nice to have someone take a new look at whatever in this stuff. My eyes dont reset very well it seems, or i'm an idiot, we'll go with the first on a good day.

I'll get it back into shape with replacing scrapped components and rechecking everything, then I'll make a new thread for it with details and pictures before I try to ask for anymore help.

So, is there a simple power tx check with a multimeter?
Thanks again!

[surfsup]

To burn up that resistor, you are pulling more than 55mA through it. Something is def wrong, the screen and two preamp stages should pull about 10-12mA -ish at idle? some shots of the power supply and power tubes would be helpful. What type of tubes are those?

[Tillydog]

So, is there a simple power tx check with a multimeter?

I really, really don't think it's your power transformer, but if you wanted to check, disconnect all the secondary winding connections and check the voltages with your DMM (AC Volts). Personally, I wouldn't bother at this stage.

To burn up R28 with no valves in place (you didn't try and fire up with valves in, did you?) you almost certainly have a short to ground on the connections that run between R28, R21, R25 & R26 (or C18 is reversed).

Check for wiring errors; stray strands of wire shorting between turrets / components and for anything touching (or even close) to the chassis under the turret board or the stand-offs.

You may as well post any updates to this thread, as the relevant info is here.

Good luck!

Andy

@Surfsup - the preamp should be 12AX7 & power should be 6V6s