Single Ended Power

[glasman]

Here is a short clip of a single ended 6V6 amp and I have been fooling around with as of late. Isn't anything Dumble about it .

1 12AX7
2 6V6 - Single ended parallel class A
1 5Y3GT

About 6 watts is all she will make. But it sounds pretty good for what it is...

http://soundcloud.com/glasman/class-a-r ... telecaster

[Structo]

Sounds nice and big like and blackface.

I really like a lot of SE designs, simplistic bliss.

[ER]

Is there any difference between a single tube and parallel tubes sound wise? I've heard mixed results on PSE. I like a 6aq5 too, gives it a small bottle sound like el-84. 6x4 rectifier for more sag and compression.

-ER

[glasman]

Is there any difference between a single tube and parallel tubes sound wise? I've heard mixed results on PSE. I like a 6aq5 too, gives it a small bottle sound like el-84. 6x4 rectifier for more sag and compression.

-ER

Well I periodically pull one tube and outside of lower output and earlier distortion the tone remains about the same. I am still experimenting with the design and still want to get a better transformer, right now there is a 2:1 impedance mismatch @ 8 ohms.

Gary

[ER]

I like the open frame 5K edcors, cheap and sound great. Come in 8 and 16 secondaries but could probably ask for a 4,8,16 for not much more. I use the 16 because I like the sound with a pair of vintage alnico 8" speakers. Made a single 12" version for my nephew that sounds nice too.

I use a loose interpretation of the dearmond RT5 for this type of amp, my next one will have a speaker tap line out. Kimock has two dumbles and uses the dearmond for slide with the line out to his dumble. We're talking about a self admitted Lindley freak with two dumbles and a signature two rock running through a ratty 1960 single ended amp to get "the tone". I talked to Kimock and he uses the old boogie style (MkIIb) slave out 1k resistor and 100k pot right off the speaker I think?

For a studio version I've always thought about running dual rectifiers, parallel octals and 7 and 9 pin tubes to mix and match for flexibility (12ax7, 6aq5, 2x 6x4, or 6sl7, 7408/6v6, 2x 6x5). Wide range of tones in there and with the line out you can take it to the stage.

ER[/url]

[Structo]

Man those Dearmonds go for some crazy money.

Is this the schematic for the RT5?

[ER]

Yeah that's the schematic I used, built point to point and used 500k instead of 650k for the tone pot, no tremelo ckt, and a 490ohm choke instead of the 500ohm resistor. Mine was a little higher than the voltages listed but probably similar to what an original would be @120v instead of 110.

[Structo]

Yeah that's the schematic I used, built point to point and used 500k instead of 650k for the tone pot, no tremelo ckt, and a 490ohm choke instead of the 500ohm resistor. Mine was a little higher than the voltages listed but probably similar to what an original would be @120v instead of 110.

Do you know what the blotted out component values are?

[Structo]

Here is a similar Supro SE amp.

A bit different on the tone control plus it uses a 5Y3GT.

[Structo]

Another modded SE amp

[ER]

There's nothing there but a 1.5k resistor V1b cathode to ground, similar to an old princeton/champ but without the 22k feedback resistor (tremelo feed instead but I left that out).

1 Meg volume. I used Mallory 150's. If you get stumped look at a tweed SE fender schematic, more similarities than differences, but the differences are important for the over all effect. Don't skip the 6x4, that's where Savage took a wrong turn in the Mahct6, I would go with dual 6x4 rectifiers and pull one when you want the compressor effect.

I also used the 15 watt edcor transformer instead of the 10 watt, some of the mojo of the original is supposed to be the oversize transformers.

[Structo]

I cleaned up that RT5 schematic.

Question, does that wire from the tone pot wiper to the volume pot wipe connect where it goes over the bottom of the volume pot?

It's hard to tell on these old schematic what is an overlap or a connection.

I have a red arrow pointing at the junction I'm talking about.

I'm thinking the tone pot wiper goes to the volume wiper, but that is kind of weird.
Not sure I have seen one like that before.

[dartanion]

Cool thing with parallel octals is that you can mismatch tubes. In my Absinthe, I am using a 35W SE OT, so lots of options exist. I love EL34s in this amp, but a 5881 and EL34 together is pretty special. Lots of other combos to try and so little time. I am also going to implement fixed bias with pots for both tubes, which will make for more optimal bias for using different tubes. Opting for the larger OT allows for this flexibility, alternatively, you could get 2 of the Edcors and use one for each tube. You could run stereo out or combine for mono.

[ER]

Connections are shown with dots, no connection there. Wipers are connected.

-ER

[FUCHSAUDIO]

Gary: have you tried a single EL_34 instead of a pair of 6V6's, just wondering ?