Looking for a preamp to build!

Dougie085

Member
2005-11-19 11:49 pm
Ohio
I've been kind of thinking about building a preamp. Here are the problems. Firstly I'd like to be able to add a digital display eventually maybe the TPA one whenever they get it together or what not. Secondly I'd like to be able to do 2.1 I'd like to try and have a sub output and I'm really not sure how to do it. So this is what I'm looking for tube or solid state and not horribly expensive. My amps right now is a ChipAmp but will probably soon be switching to the Ref RevC. Source is a TPA Opus DAC with USB and SPDIF inputs. Not really sure what other input you guys think I should include?
 
Well I can't help you with the display aspect, as I think that would involve a much more complicated circuit that most DIY pre-amps have, but around here many people recommend the 'pumpkin' pre-amp.
Pumpkin

I personally went with Hugh Dean's GK-1m (its a tube based pre-amp, wonderful little thing).

here is someone with a display:
Video
Very basic, but it works

I would think the best way to do the display would be to build a separate circuit and link it into the preamp circuit, but for audio...the preamp circuit should be your main focus.

-West
 

Dougie085

Member
2005-11-19 11:49 pm
Ohio
Yeah the display would basically be the source switcher and volume control and a few people sell them. Twistedpear is supposed to have one eventually its just been a long time in the making :) I thought the pumpkin was a really high gain preamp for like the F4?

I thought about doing an Aikido but I'm not sure how to do the sub output.
 

kuroguy

Member
2007-09-08 4:32 am
I'm working on a line preamp which has a LCD display and BasicX BX-24 microcontroller that will control the LCD and a set of relays to switch sources. I also plan to use the BX-24 to control a motor pot for volume. The BX-24 can be had for $39 and an lcd can be had for $15. I'm currently writing the code for the microcontroller and designing the relay board. Hopefully I'll have it complete in a month or two.
 
kuroguy said:
I'm working on a line preamp which has a LCD display and BasicX BX-24 microcontroller that will control the LCD and a set of relays to switch sources. I also plan to use the BX-24 to control a motor pot for volume. The BX-24 can be had for $39 and an lcd can be had for $15. I'm currently writing the code for the microcontroller and designing the relay board. Hopefully I'll have it complete in a month or two.

Is there a reason why you decided to go with a potentiometer instead of a digital volume IC like the TI PGA23xx series? It's seems like an awful waste of a microcontroller just to use a regular pot.
 

kuroguy

Member
2007-09-08 4:32 am
theAnonymous1 said:


Is there a reason why you decided to go with a potentiometer instead of a digital volume IC like the TI PGA23xx series? It's seems like an awful waste of a microcontroller just to use a regular pot.

Actually, the Microcontroller is necessary in order for my wife to be able to use the stereo. I would have been content with a passive source selector box with volume control. As these things tend to get complicated I figured that it would be easier if there was a plain english display showing her what settings to make on the preamp. It also makes it easy to configure many switches with the press of a single button.