2 builds going - 1 close to power up

[stelligan]

Finally back to some building after a long bout with tendon trouble. 2 builds going now. One 50 watt 6L6 D'Lite with some twists. Started as an HRM on main board and yanked everything when the rash of RF and 183 info hit the a garage. Allen Bassman/Bandmaster PT and HRD OT(all I had). Probably will be hearing it by Sunday. Another is a Bluesmaster in a Funk chassis. Magnetic Components PT and Heyboer Twin OT from Brandon. That one is farther out, but making headway. Using spare parts and resistor pulls. - there are some 1/2 watt resistors in places , but hoping all comes out alright. Thanks to: Tony, Shad, Brandon, Henry, Scott, Brian, Mark and all contributing here. I am sure these will be my best sounding builds to date thanks to all the great info being shared. Tony's layouts are killer. Thanks y'all!!

[Bob-I]

Looking good.

I gotta get myself in gear and get some amps done. I have 2 started and a 3rd being planned. All will use pulls for most components including iron pots and some resistors. Caps and sockets will be new.

[stelligan]

Looking good.

I gotta get myself in gear and get some amps done. I have 2 started and a 3rd being planned. All will use pulls for most components including iron pots and some resistors. Caps and sockets will be new.

Thanks for checking it out. I will be powering up tonight with a light bulb limiter after I cannibalize some 1 ohm resistors out of an Silvertone I put bias points in a while back. Keep telling myself that these are the last 2 amps, but need to order a few more parts. Replace the resistors for the Silvertone - then I'll order extra of what I need in resistors - then end up with spare parts - then another board gets cut.........

Those solder fumes must be like crack - or it's these amps...............

[Structo]

Looks like fun Dave.

On the D'lite amp, I don't see a OD trimmer.
Are you putting the control on the back panel?

[angelodp]

Dave, I have my Dlite in the 6L6 mode as well. What values are you using on the tone stack and other changes from the base Dlite scheme if you can. How about the PAB are you using the standard method or tying the bass and midpot.

happy startup

Ange

[talbany]

Dave
The builds look great!!.. Wishing you a smoke free startup..

Tony

If it's loud and proud then you built it right..

[stelligan]

Looks like fun Dave.

On the D'lite amp, I don't see a OD trimmer.
Are you putting the control on the back panel?

Tom,

It is fun - and nice to have two functioning hands for a change, too!
The OD trim is on the front panel. Those two pots in the center with switches on the back are OD trim and Bass. The bass pot will switch PAB on when full off and the OD trim will switch the OD off when full down. I plan on marking the front panel at 26K as a reference.

Dave, I have my Dlite in the 6L6 mode as well. What values are you using on the tone stack and other changes from the base Dlite scheme if you can. How about the PAB are you using the standard method or tying the bass and midpot.

happy startup

Ange

Ange,

This preamp is set up very much like that #102 RF amp that Tony chronicled and laid out in the files section. No rock/jazz switch or deep. .01 mid cap, 120pf bright switch, 68pf cap on master, presence like 183. The PT is 340-0-340 and I anticipate playing with the dropping string to get voltages down. I don't use PAB that often on a non-HRM like this, but I will try both methods and decide what sounds best. We'll see. If it sounds good - I'll go into more detail.

Fingers crossed.

Dave
The builds look great!!.. Wishing you a smoke free startup..

Tony

If it's loud and proud then you built it right..

Thanks!
I am hoping for the best. Many thanks to you for the great layouts. I would not be this far without them as I am very poor at schematic reading.

I pray for a smoke free environment this evening.......

[stelligan]

Powered up this am instead of last night. Out to dinner and too much chianti to risk a high voltage event.......

A few snags, but not bad. PAB was wired backwards - no biggie. Powered up great voltages OK. Why no sound??? Errr.. 220k & 500pf at V1 wasn't there!? After that stuff fixed, it is now up and running. PI has a 5k trimmer and I am having trouble getting that where I want it. It seems to do next to nothing for me and I need to investigate.

How does it sound? Meh... Needs some help from y'all.

Voltages feeding preamp board are: 448v, 333v, 325v
V1: 194v, 200v
V2: 191v, 235v**
PI: 312v, 304v

150k & 220k at V1 and V2

Preliminary wankage sounds like this:
http://www.luckystiffs.net/poweruptest.mp3

To do list: tweak PI, try to get rid of some harshness when hit hard, wire footswitch jack. Find some octal and 9 pin hole plugs. No bright cap on master yet*

Pics below.

[Structo]

V2 voltage is screwy, try a different tube there.

I like about 195v on V1 and 200-210 on V2.

Sounds nice, clean tone is great.

The OD tone not so good, sounds like the entrance trim isn't quite right.

So investigate why that plate voltage is wacky on V2 and try for about 25-30K OD trimmer wiper to ground with amp on standby and OD switched on.

[stelligan]

V2 voltage is screwy, try a different tube there.

I like about 195v on V1 and 200-210 on V2.

Sounds nice, clean tone is great.

The OD tone not so good, sounds like the entrance trim isn't quite right.

So investigate why that plate voltage is wacky on V2 and try for about 25-30K OD trimmer wiper to ground with amp on standby and OD switched on.

Thanks for taking a look, Tom. I am on my third tube in V2 with no good movement on that high voltage. I'll look for some old JJ for that spot. Seems to me some of those can suck the voltage down at times. May have to increase a resistor value in that path somewhere...... Regarding the trimmer. I measured 26k with OD off - I'll try it on. Thanks

[ChrisM]

Did you measure your plate and cathode resistor's on that triode before you installed them?

[stelligan]

Did you measure your plate and cathode resistor's on that triode before you installed them?

I did not. I may yank them and measure. Try carbon comps there if the RN65 are out of spec - then order more parts....... Bummer.

I need to peep V2 real good and see if there is something boneheaded there as well. Thanks for the advice.

[Bob-I]

Did you measure your plate and cathode resistor's on that triode before you installed them?

Also, check that the cathode's aren't reversed, V2a cathode resistor wired to V2b. I did that once and had exactly the same results.

[stelligan]

Did you measure your plate and cathode resistor's on that triode before you installed them?

Also, check that the cathode's aren't reversed, V2a cathode resistor wired to V2b. I did that once and had exactly the same results.

Thanks for the idea, Bob-I.
That is quite possible. I did a funky thing on this build in that I have the V1 tube socket oriented opposite of the other two. Too lazy to yank it and reverse once I wired a few things. So I was thinking backwards when wiring sometimes. I thought I triple checked, but it's time to fourple. It will have to wait 'til the Packers kick the Bears' asses, though......

[Bob-I]

Thanks for the idea, Bob-I.
That is quite possible. I did a funky thing on this build in that I have the V1 tube socket oriented opposite of the other two. Too lazy to yank it and reverse once I wired a few things. So I was thinking backwards when wiring sometimes. I thought I triple checked, but it's time to fourple. It will have to wait 'til the Packers kick the Bears' asses, though......

The way I found it was to measure from the tube socket to ground. Where I thought I should see 2.2K I saw 3.3K