This ones for you "tubewell"

[ivey]

I have not been on later due to illness. I got good news from my doctors, not the best, yet surely not the worse. Hopefully I can start work in my shop again.

So I am using my grand kids, to help me out. They are so full of energy. It tires me out. They build these, with my guidance.

But God, do they just love to learn things from their Grand Pa.

So o.k, TubeWell, here goes.

I am building a Twin Reverb Amp. I am using 6DQ6A's a favorite of PlayMaster. In fact, I copied the PlayMaster 116 circuit, since I have about twenty of those tubes handy. Driver tube is a 6GH8. PreAmp tube is the 12AX7, with Fender circuit tone stack.

I am using IRF820's in the reverb drive and recovery circuits, as well as the tremolo circuit. Speakers are Jensen's Mod 12" @ 100 watts each, using two speakers. I may add two more and go Super Reverb.

So here is the circuit board pictures. Kids did a good job, listening to their Grand Pa. And my wife said they would get bored. I had to force them to go home. They love this stuff. And man do they have questions!

Take Care

Ivey

It will look like a Fender Twin Reverb Amp, when done. And I hop that it sounds good.

[ivey]

Tube Well, how are you, down under?

I almost got the tube unit electronics done, and I am now working on the wood parts. But I am also building a solid state amp as well. Both will be 60 Watt units.

I am using the Red Circuit 60 watt amplifier, only it does not put out 60 watts as it was designed. It is more like 40 watts. I improved the design and given it more drive and voltage/current. I did not use the preamp of the design. I am using the Gibson G100A preamp. I modified it by using MPSA18's in place of the 2N2484's and changing the values of components to improve it's tone. I also included a Univox tremolo circuit.

I posted pictures of the power supply, voltage regulators and power amp. I really reduced the power amp's size. Using the best I could obtain.

I hope to have one of them done by Sunday

Take Care


Ivey

[tubeswell]

Hiya Ivey, I just saw your thread - I was away for a bit in Dec and Jan on 'family business' and I only got back on the board in the last couple of days. Have you got a schematic you can post?

[ivey]

Yes, I do. I will have to get them all together and post them. They are circuits from different amplifier designs, drawn together to use all the items that I have in my Junk Box of parts. Without having to purchase too many new items.

In all TubeWell, I am building three guitar jazz amplifiers. One will be 60 watts, designed as a tube hybrid Fender Twin, using the Old New Zealand's Playmaster 116 guitar amplifier power amp design, that used 6DQ6A output tubes. Since I have those around, I am using them in the design, with one 12AX7A in the tone stack. Reverb and Tremolo circuits are IRF820 driven. With two 10 in. speakers @ 100 watts each.

The second is also 60 watts, using the Red Circuits 60 watts design. Only I discovered that the way it is design, it will not put out the power as stated. So I beefed up the power supply and added more drive. And got the 60 watts for single 12 in Jensen Mod 8 ohm speaker.

I change the front end of the Red Circuit. I replaced it with a Gibson front end from their G100A guitar amp, that I laid out in QuickRoute. I did 15 layouts and circuit changes. Built it, and ran it through my headphone amp. The tone was remarkable. And I used a simple tremolo circuit from the UNivox URN65.

The final build, will be 90 watts, all jfets and Mosfet Twin Reverb. Using two salvaged Philips 12 in. 150watt guitar speakers. Using the Gibson front end tone stack, the heathkit's TA-17 reverb and tremolo circuits, modded to use jfets. You use less parts, with jfets. And the 2N3819's are simple to use and trim.

I am gathering circuits from different makers of DSP circuits to design, layout, and build, once the three amps are done. The unit will be designed and laid out to look like an old Moog unit. So that I can use some of my old junk box logic chips and ic's. It will be 16 bit, so I will use up some parts. Especially all those damn 1N914 switching diodes, that I have around.

I have circuits of the early Moog's, but they use RTL logic chips. Not TTL. And I have to see and study with ones I can design in and out. I do not have RTL chips. They were not around long enough to get my hands on. I have TTL chips. Plus I want to use all these LM741 TO8 cans that I have around. That I picked up at a Ham Fest.

All my CAD/CAE designs are done in QuickRoute. The company was in business out of England, and now is no longer in business since 2003.
Unless you use QuickRoute, it is hard to transfer data. I can supply PDF files.

QuickRoute is really cool stuff. I discovered that I can read and print any QuickRoute program's bottom and top layers. I can not do the silk screens but I can do the ones just mention.

So if anyone out there is using a QuickRoute Dos programs and want to produce a good quality PDF file for "toner transfer" here is how it is done.

Go to SimTel, and download QuickRoute 4. Then download BullZip PDF Printer/ with the Ghost Converter. Also download Foxit Reader. Then remove your Adobe Reader and install all four programs.

Using your QuickRoute Dos program. Save your pcb files bottom layers and top layers in seperate files at 1:1. Using the QuickRoute 4 program, load those files and print using the BullZip PDF Printer.

The Dos files will load into the schematic capture section, and will be printed from that section to scale.

I use QuickRoute 3.6, 4, and QuickRoute's Electronic Design Studio 3.3

Take Care

Ivey