No frills tube pre ? perhaps.

[Bostown]

I need another preamp like Hugh Hefner needs another blonde bunny at the Playboy mansion.

but in the name of experimentation and curiosity ...
This magi look alike isn't too shabby for what it is and I can always use another phono pre I suppose.

 

[jaymanaa]

I take it the tubes under the shields are AX7s and the phono amp, and the line stage tubes are 6SN7s?:scratch2: Rectifier almost looks like a 3DG4.

 

[Bostown]

I take it the tubes under the shields are AX7s and the phono amp, and the line stage tubes are 6SN7s?:scratch2: Rectifier almost looks like a 3DG4.

yuup. pretty much.

2 Electro Harmonix 12ax7eh
2 Eico (westinghouse) 6SSN7GTB
1 5Y3GT

looks like it might be built in a case belonging to something similar to this thing

 

[mhardy6647]

it's custom!

;-)

 

[Bostown]

it's custom!

;-)

"Custom", is fine I suppose, so long as it holds up and serves it short term purpose. , and although I wont be using them together, I have my fingers crossed that the unit in the following photo was "made in the factory".

 

[jaymanaa]

I like it, it looks well laid out and has some decent power iron, (something a lot of tube pres scrimp on). let us know

 

[Bostown]

The mystery Pre-amp has been a part of the pre-holiday music system for the past month or 2 and has done a great job overall. - I'm still no closer to finding out who built it although It's suspected that Mark Voigt might be the person behind it. I believe he's on AK as "soundbug1" I need to reach out to him via his ebay store and see if he can I.D this unit.

but no complaints here. It sounds great running with a pair of SS Marantz MA700 mono amps. - The phono stage is pretty decent as well. - If I ever get around to bringing the pair of crusty Dynaco MK3's i have back to life. this might just be the pre-amp to marry them with.

 

[Rob Santry]

Hey Guys,

Nice post Bostown! I'm thinking, does anyone know if there is a circuit diagram and parts list around to build something like this? I'm looking to try something different to connect to my Dynaco MK III's...

Rob

 

[jaymanaa]

Ha, I'm running a Denon sand pre (because it has MC phono) into tube amplification.

As far as designs, if you want a very simple terrific sounding linestage google 12B4 designs. If you need phono RIAA check the back of the old RCA manuals, they had a good one. If you want to go high end with a kit, look at Jim Hagermans site Hagerman Technologies. No secrets with Jim, it's all right there to download if you want to build it on your own chassis point to point. He even gives you a Mouser / Digikey parts list last time I looked.

 

[Bostown]

Ha, I'm running a Denon sand pre (because it has MC phono) into tube amplification.

Denon pre-amps ( PRA 1100,1200,1500 DAP 2500, and 5500) .. are pretty well underrated units if you ask me. Not all have phono preamps ( the 5500 DAC/LINESTAGE doesn't) but it's built like fort knox.

I still have a 2500 and 5500 in the hoard.

 

[Bostown]

I'm reviving an old thread since I have some nudies from under the hood and got a confirmation from Mark a while back , that this is indeed one of his early units.

Still a solid little monster.

 

[mhardy6647]

Nice looking piece of hardware. Built with care.

 

[mrwood200]

agreed! impressive.
And good job with the photos! I appreciate the orientation/order; made it easy to view.

Any other insights into the circuit? You think this is a 'magnavox' clone??

 

[Bostown]

agreed! impressive.
And good job with the photos! I appreciate the orientation/order; made it easy to view.

Any other insights into the circuit? You think this is a 'magnavox' clone??

Not exactly sure , but it certainly worked well with the units i paired it with over the years that I owned it. It's now found a new home with another AK member. He may eventually chime in with more pics and impressions once it touches down at his place later this week.