I've built some amps, need suggestions for a DIY preamp or line stage

[jduffy]

I've built a chip amp from scratch, a tube amp from a kit and would now like to build a tube preamp or line stage. Cheaper is better and I found it fun getting good parts for my chip amp at low cost.

It would be nice to find something with three lines in and two lines out. I listen mostly to jazz, blues, and classical.

Can you point me to some good schematics and plans that I should consider for this project?

Thanks for your help.

 

[jaymanaa]

The thread of all line stage threads http://www.diyaudio.com/forums/showthread.php?s=&threadid=68267&highlight=

 

[kstagger]

I've had good luck with the Ultrapath transformer coupled 6J5 linestage - though power supply design must be carefully designed to minimize hum. On the weird side, I really like the triode connected EF86 and C3m... very musical and they sound a bit different than the usual 12A*7 stuff.

 

[billbo]

valve line stage preamp

If you want to build a simple and good preamp go to this link below. I have posted my scematic which I have built.
Cheers

http://www.diyaudio.com/forums/showthread.php?threadid=91800&perpage=10&pagenumber=5

 

[jduffy]

Thanks

Thank you for the help. I'm still considering options.

If there are more, I'd like to hear them.

 

[Steve Cresswell]

You could try this one
I have used it for 12 months and it sounds great very low noise indeed.
PSU included.

Steve

An externally hosted image should be here but it was not working when we last tested it.

 

[jduffy]

Thanks for the schematic Steve. I looked up the 6J5 and it sounds like it would work for me as I like good mids and highs as I listen mostly to jazz, blues, and classical.

 

[talaerts]

Well, the aikido (see www.tubecad.com) should be a very good preamp, and it's handy that you can order the very high quality pcb for it.
I have -finally- started building it, using 6GM8 low-voltage tubes (needs a 24V power supply). This uses the 9-pin PCB.

 

[jduffy]

I looked for an Aikido preamp but all I saw was an attenuator.

Is there in fact an Aikido preamp PCB?

 

[Nordic]

Yes, and many versions... all the rage these days...

 

[talaerts]

> Is there in fact an Aikido preamp PCB?

Yes.
You may want to read some of the Aikido related blogs on tubecad.com
It all depends on how much amplification you want.
for a standalone preamp, that's probably not very much.

This reason, plus general curiosity, lead me to order the stereo 9 pin Aikido PCB that I will be using with the 6GM8 tube, which is a low voltage tube: the power supply is only 24Volts.
It is said to sound clean and it can amplify 15 db. Which should be enough.

If you search the tubecad page for 6GM8 and 24 then you will find all info, including a regulated PS design.

I am also making the stepped attenuator kit for the volume control.

Tom

 

[jduffy]

Really?

I have to look harder at that website then!

Thanks for the help....

 

[Beelzebub]

Really?

I have to look harder at that website then!

Thanks for the help....

Hi jduffy, try this, linked from Tubecad home page
http://glass-ware.stores.yahoo.net/newhardware.html

 

[Beelzebub]

Hi jduffy, try this, linked from Tubecad home page
http://glass-ware.stores.yahoo.net/newhardware.html

Oh, and check out this page:
http://www.tubecad.com/2006/05/blog0064.htm