Pre-Amp

[TheDriver41]

I have completed my gainclone using Brians kit and I'm very pleased. I am running a pair of fostex full range f200a in a pseudo-bass reflex by JohnK.

Right now I'm using my cheap apex dvd/cd as my primary source. I made my GC with only one input and no volume control because my dvd player has variable out.

I was thinking since the source did dvds and cd it would cover my music and movie needs. But now that I got TV on demand I will be watching movies with my cable box as a source. The cable box has variable out but doesn't put out stereo unless it's turned about 75% up. At this point I knew I would need a pre-amp not only to select the source but to control volume.

I have been researching pre-amps and have run into a few problems.

1) I'm happy with my NIGC but want to build a regulated VBIGC next. I don't know alot about pre-amps but I do know they have a buffer. If I include a valve buffer in my pre-amp would I need one in my amp? How can I build my pre-amp with this future amp in mind?

2) I read nuuk's gc pre-amp section and am curious about sonic qualities of a ic pre-amp over valve. I'm seeing more and more VBIGC coming up. I'm assuming the pairing of a valve buffer and gc works well.

3) I want to build a pre-amp of great quality. What switches and volume controls are recommended?

4) Is Allen Wright’s pre-amp cookbook worth the price?

Thanks,
Matt

[moamps]

Originally posted by TheDriver41
1) If I include a valve buffer in my pre-amp would I need one in my amp? How can I build my pre-amp with this future amp in mind?

Hi,
You don't need an additional buffer in the amp if your volume control isn't connected between the preamp and amp(IGC), i.e. if the chain is "input selector-volume control-buffer-interconnect-amp(IGC or NIGC)".
You can also build a separate tube preamp-buffer with several tubes (ECCxx, 6sn7, 5687..).

I'm assuming the pairing of a valve buffer and gc works well.

Yes, IMHO.

3) I want to build a pre-amp of great quality. What switches and volume controls are recommended?

Depends on your budget. Search this forum; you will find a lot of ideas. Transformers in volume controls sound best to me. (S&B, Sowters). I've been listening over the last couple of days to my own autotransformer volume control design with TBIGC and I'm very happy with the results.

4) Is Allen Wright’s pre-amp cookbook worth the price?

What's the price?

Regards,
Milan

[Nuuk]

2) I read nuuk's gc pre-amp section and am curious about sonic qualities of a ic pre-amp over valve. I'm seeing more and more VBIGC coming up. I'm assuming the pairing of a valve buffer and gc works well.

The pre amp on DD uses a discrete transistor circuit, not an IC!

The sound quality of that circuit, and Pedja's discrete Jfet circuit, clearly outclasses the VBIGC as described on DD. I appreciate that a better valve buffer based on something like the 5687 will sound better than the VBIGC but then you are working with 300 VDC rather than +/-15 VDC!

But you can build a pre amp and try a variety of buffers while still keeping the rest of it intact!

For the work involved, and the low cost of the DD pre amp buffer, it is surely worth building if for no other reason than to have a benchmark by against which you can xcompare other buffers. You might be pleasantly surprised!