6SN7 Pre-amp

[The Shadow]

Hi James,

Don't worry about the manner of your reply etc.

I'd rather somebody come straight out with an opinion or advice than give a politician's answer. I had enough of that when I was full time at school.

The fact is that Paul and yourself are not jumped-up bureaucrats telling me I don't know how to do my job. You do actually know what you are talking about, therefore it would be foolish not to take your advice seriously.

For example Paul's initial comments concerning the use of paralleled 6SL7s for the power amp were pretty withering in their condemnation of that set-up. But I listened to him and in conjunction with his further advice, grounding the suppressor grids on the output valves resulted in an amp that sounds marvellous instead of one that I would probably have been disappointed with.

I've copied, pasted and printed out your reply so that when I have a go at another preamp or mod the existing one I'll have a far better basis to start researching than I had when I built the present one.

Edit my version of the circuit is up if anyone wants a look http://homepage.mac.com/scress1958/S...Sharing40.html

Steve

[simon2a3]

Originally Posted by The Shadow

There's an amp shootout arranged for this weekend.

Read all about it next week on the website.

See how Rocky the EL34 and his little brother fare against a pair of 300B monoblocks.

Will Rocky get sand kicked in his face. Will he hold out against Western Electric's finest?

Blimey Steve, I didn't realise it was going to be competitive. I'm going home right now to start polishing the fuses...

Simon.

[The Shadow]

Just kidding Simon

Steve

[The Shadow]

James,

I've put the op point back to Olsher's

You were absolutely right of course about the load line descending into distortion very rapidly with the bodged op point I chose. Why I didn't see it I can't imagine!

It's either Olsher/Chaffee's way or MJs. You can't just bodge a compromise without a proper redesign.

There I've learned something else