Teeco 610D conversion

[sluckey]

You mean the 22k in the Rock-o-la? Might there be any sound clips of this amp?

No. I'm talking about the 36K in your Teeco. May as well label that NFB switch as NONE and ALMOST NONE.

No sound clips. The amp sounds very Fendery.

[angelodp]

But with that 36k I do get quite a change in the amp when I engage the switch. It does boost the signal a fair amount. 36k lower gain, less distortion, no 36k - louder and more dirt.

[angelodp]

I would put the TS between the triodes. Here's a proven circuit. And the typical slope resistor works just fine. If I had to buy a 6SL7 I'd probably get a JJ simply because of the price.

http://sluckeyamps.com/rocky/rocky.pdf

sluckey, what is the 1540 arrangement in the power string about?

[sluckey]

It's a 1540Ω power resistor with a center tap. Equivalent to two 770Ω resistors in series. It's old technology. Pic may help...

rocky.png

[angelodp]

I could use two 770R in series if I can't find that device.

Thanks A

[sluckey]

I wouldn't even bother looking for that obsolete resistor. There's nothing wrong with the power supply that's already in your amp.

[angelodp]

Great - thanks - I am working on a graphic layout which I would appreciate any feedback on.

Best A

[angelodp]

On the Rock-O-La I see 375-0-375, my PT is putting out 350-0-350, but I am going with 6V6. I think that will work out?

Best A

[sluckey]

Don't you already have a working power amp and matching power supply? Stay with that. I showed you my Rocky just so you could see how my 6SL7 preamp and TS was wired. There's stuff in my power supply that was there when I converted that juke box amp to guitar amp. My amp originally had to supply a field coil speaker. That's why you see those oddball high power resistors. Your power supply looks just fine for your 6V6 amp.

You may not have seen my info on the Rocky conversion so here's the link if you want some more background on Rocky...

http://sluckeyamps.com/rocky/rocky.htm

[angelodp]

Copy, moving ahead with Rock-Ola. Question. The Teeco used a grounding scheme that tied all the tube sockets to ground. I think I am safe to eliminate that in favor of a simpler ground scheme?

A

[sluckey]

My Rocky has all the sockets and cap cans tied to chassis with a bare #22 wire. That's just the style with good quality PTP amps from that era. Tube sockets usually had 4 solder tabs just for that purpose. Works fine.

[angelodp]

Copy thanks. Since I am switching out the 6SC7 for 6SL7 - V1 pin 1 had a ground on it.... not bueno. Just realized that and cut that out since the 6SL7 uses pin1. That would have been interesting

[angelodp]

sluckey,almost there. Question. With the Rock-Ola am I ok elevating the heaters at the 6V6.

Ange

[angelodp]

Ok, I need some help with the dropping resistors in my B+ which are not working as before.

I rebuilt the amp using the Rock-Ola design, except that my power section is for 6V6 and has differing dropping R's. Tested for shorts with limiter and all is well. My first B+ node (with just the Rectifier installed) is at 440VDC. My first dropping R is 3.2k 3W and it is not dropping anything. B2 is right at 440VDC. Further down the line I have a 36k R for the PI and V1 and I don't see any drop there either (no tubes installed). I have 440VDC all the way across??

I will submit my build photo, any advice on how best to proceed?

[sluckey]

No tubes installed = no current flow = no voltage drop.

Put the tubes in.