Search found 15710 matches

by Nick
Wed Nov 12, 2008 5:00 pm
Forum: Beginners
Topic: Buffer/unity gain amps.
Replies: 146
Views: 57936

Nick, so your buffer as you say feeds straight into a TVA ( a stepped transformer yes?). The way in which you've done that is to maintain the source impedance closer to it's desired value, and thats more desirable than o/p impedance being maintained yes? Almost, The reason I use the buffer is I lik...
by Nick
Wed Nov 12, 2008 3:06 pm
Forum: Beginners
Topic: Buffer/unity gain amps.
Replies: 146
Views: 57936

One thing I don't understand though is how the turning volume control doesn't affect the i/p and o/p impedance's in a buffer amp where as on my pasive pre it's obvious how a big pot strapped across the o/p of the source and i/p of a power amp isn't a good idea. If you have a pot going onto the grid...
by Nick
Wed Nov 12, 2008 12:34 pm
Forum: Valves
Topic: Heater connection for minimum hum - 6072/12ay7
Replies: 20
Views: 15110

I think all they are trying to say is the heater should be -ve WRT the cathode. Isn't that contrary to conventional wisdom, though, as that would effectively "turn on" the parasitic diode between heater and cathode? Well, that would be the case if the conduction was through free electrons...
by Nick
Wed Nov 12, 2008 12:28 pm
Forum: Buying and Selling
Topic: bits for mr I's 45 pp amps
Replies: 34
Views: 14632

I am not sure if they are designed to handle DC on the primary side.
by Nick
Wed Nov 12, 2008 12:20 pm
Forum: Valves
Topic: Heater connection for minimum hum - 6072/12ay7
Replies: 20
Views: 15110

I think all they are trying to say is the heater should be -ve WRT the cathode.
by Nick
Wed Nov 12, 2008 11:53 am
Forum: Valves
Topic: Heater connection for minimum hum - 6072/12ay7
Replies: 20
Views: 15110

With connections to pin 9 and pins 4,5 you're connecting the heaters in parallel. I'd expect that an elevated supply is the way to go. If you're AC heating, I think you should create a virtual centre tap and connect this to the elevated supply, 20V is probably about right. I certainly wouldn't conn...
by Nick
Wed Nov 12, 2008 11:47 am
Forum: Buying and Selling
Topic: bits for mr I's 45 pp amps
Replies: 34
Views: 14632

by Nick
Wed Nov 12, 2008 11:45 am
Forum: Buying and Selling
Topic: bits for mr I's 45 pp amps
Replies: 34
Views: 14632

I looked at the hammond interstages and I don't think they will do the job.

Of course, no one did say the amp was do-able at low cost, and if its done it may not be anywhere as good.
by Nick
Wed Nov 12, 2008 8:08 am
Forum: Assorted Stuff
Topic: 8/9th November Owston meet
Replies: 224
Views: 84435

Ali took the valves with him.

Steve: re the forum, its rearly nice for you to say that, and thats how I hope it is, but that doesn't mean I can assume that :-).
by Nick
Tue Nov 11, 2008 9:17 pm
Forum: Buying and Selling
Topic: bits for mr I's 45 pp amps
Replies: 34
Views: 14632

Hammond 1608 or 1609 would be fine, and to save more 125H
by Nick
Tue Nov 11, 2008 4:44 pm
Forum: Buying and Selling
Topic: bits for mr I's 45 pp amps
Replies: 34
Views: 14632

I haven't got any, but I would have thought they were more likely to be 10k a to a for a pair of 45's so each 45 sees 5k. But I don't know what Andrew is using.

I think his were from Majestic FWIW.
by Nick
Tue Nov 11, 2008 12:40 pm
Forum: Assorted Stuff
Topic: Owston Photos - 8/9 November 2008
Replies: 30
Views: 17870

It was just a suggestion at best, If you look at it democratically then only those people that don't cache will vote against embedding(likely zero people) and Nick if he's short on disk space(unlikely) so forget I mentioned it... Well, it is a finite resource, so its better if you can, (from my per...
by Nick
Tue Nov 11, 2008 10:45 am
Forum: Assorted Stuff
Topic: 8/9th November Owston meet
Replies: 224
Views: 84435

That's fine, Nick, it's your forum but you might wish to consider the image you're portraying to the outside world and other enthusiasts not part of 'the gang'. I shall say no more about it. Yep, you are right, it is my forum, and I am entirly happy with the image its portraying thanks. Steve: I ho...
by Nick
Tue Nov 11, 2008 8:04 am
Forum: Assorted Stuff
Topic: 8/9th November Owston meet
Replies: 224
Views: 84435

and you're right but an SP10 with a Hadcock arm (Nick's deck) for example is also a commercial product And I should point out I didn't bring the sp10, so I fail to see it as having any relivance? I don't mind honest comments like yours, but some of the other ones on this thread *are* OTT, IMO, and ...
by Nick
Tue Nov 11, 2008 1:22 am
Forum: Valves
Topic: Andrews PP 45 Amps
Replies: 18
Views: 10443

No, not a explanation by any means, though I agree the PP amps that work best for me do use a IT splitter, the WAD one and so on. No, the thing that I found interesting, was how different the 45 PP sounded to the SETs there, I have no intention of this being a "whats better", or even a &qu...