Custom Preamp Project

[glasman]

Front panel closeup.

I generated these panel in house on my new to me epilog Helix laser.

Looks great what material did you use for the face plate?

It is a two layer black over white plaster laminate. Very tough, Used it on my ZIngaro amps for the last few years. Much stronger than the acrylic that I used in the past.

Gary

[glasman]

To clarify for Martin, it is close to the standard CF section, I just rebias that section to get more headroom. The standard values suck and it will clip in a heartbeat.

Thanks. That means you have an unused triode?

Super low-ripple power supply and DC filaments are to be expected for a piece of gear like this.

The two halves of the triode are wired in parallel, same as I do on my Matchox two channel d-lator.

[glasman]

This piece was commisioned by Rick Derringer of all people.

Very nice and neat. Classic look. Super job of fitting 8 lbs in 5 lb box.
Rick Derringer is one of my favorite guitarists. (Very underrated)
I don't think I've seen him use rack mount gear.
I'm sure he will enjoy it.

Denny

Rick was telling me that the last few years he has been carrying a rack style preamp that he simply runs into the power amp input of a Blues Deville, never uses the clean just leaves the preamp in Overdrive Mode. His first was built by VVT I think, guess they had an issue with the unit and decide to contact me for a new unit. I really hope it meets his expectations. Have a LOT of hours into it at this point.

But it does give me the desire to finalize my rackmount preamp for studio or stage use. started the design a few years ago and never finished it lol.

Gary

[glasman]

To clarify for Martin, it is close to the standard CF section, I just rebias that section to get more headroom. The standard values suck and it will clip in a heartbeat.

Thanks. That means you have an unused triode?

Super low-ripple power supply and DC filaments are to be expected for a piece of gear like this.

Yes, I went very stiff on the power supply for that very reason. Also the reason I included a choke in the design. The ripple is literally in the noise on the DC lines.

Gary

[jelle]

Looks great Gary. Very nice work.

[glasman]

Looks great Gary. Very nice work.

THanks Jelle.

[tubedogsmith]

This is similar to what I did, but i mounted the boards Dumbleator style.

Preamps can be tough with noise!I had to mess around with the grounding for quite a while. Shopping for a PCB house now for mine. I also did a passive and buffered output, with a full loop. Mine looks much more crude Yours looks really great Gary!

I used a full wave bridge as I'm not a fan of voltage doubler's. Had Heyboer make me a PT with a 260v secondary in an R2C frame.

Do you notice much of a "smoothing" effect with all the shielded connections.

[glasman]

This is similar to what I did, but i mounted the boards Dumbleator style.

Preamps can be tough with noise!I had to mess around with the grounding for quite a while. Shopping for a PCB house now for mine. I also did a passive and buffered output, with a full loop. Mine looks much more crude Yours looks really great Gary!

I used a full wave bridge as I'm not a fan of voltage doubler's. Had Heyboer make me a PT with a 260v secondary in an R2C frame.

Do you notice much of a "smoothing" effect with all the shielded connections.

No not really, the lengths of the cable are pretty short so there is not much net capacitance. The chassis is only 8" deep. Life would be nicer if I were to implement some right angle tube sockets lol. The space between the l-bracket for the tubes and the board is a PITA to work on. But it is a one-off and there will probably never be another quite like it.