|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
67.189.228.172
In Reply to: feedback on b+of circlotron posted by tubevibb on September 1, 2006 at 05:38:19:
2-3Ku is low for a circlotron of any meaningful power output and low frequency use.
What is the B+ voltage?
Are the two power supplies truly floating and independent?
What are the tubes in the o/p stage?
How many?
Amplifier output impedance?
Load?
The 1K will affect the plate to cathode voltage. Are you sure the bias is correct/optimal?
What Class of operation are you using?
The .5 ohm in the cathode will raise the bias voltage and raise the output impedance. Is this really want to do?
=
Follow Ups:
Good there is life?too caps on each amp each cap +/- so u run 1k from+/+ OR PLATE TO PLATE ON THE AMP do both amps it has to help dc offset.my M60 DIY MA1 HAD 1ohm on plate not right. out. now 5. ohm on cathod better bassss better all way round .if it good for atma-sphere it goood for me. now the 500 ohm 2k 3k sound diff. i am in to sound u r to but u may not be a diyer thanks t.v.
Hi All - I have just about finished wiring my second monoblock with the 1 ohm resistors into the plate section ...Now reading with interest about the 5 ohm @ 5 watt ....Learning that lower ohmage has less sonic importance - so what type of 5 ohm , 5 watt resistors are you using ??? - And is anyone going to post a picture of them in place ? .Im thinking of the room that these would take up ... I have 1 ohm @ 3 watt in place at present . The main reason I would be considering this modification ( after fully testing the amp with SPEC components / as per drawing ( thx ralph ) ...is that the tube lifetime would be enhanced . And I can already say that Ive seen the difference in the tubes without a tube tester . The temperature of some tubes is very different ...and if the 5 ohm resistors helps load matching better than 1 ohm resistors ( for the sake of the tubes ) then I must look into rewiring the chassis's at some point .
But not untill Ive heard them both in the spec design state first .
Yep; 5 ohms is "better" than one ohm, in theory, but the 5-ohm R will raise the output Z a little more than will a one-ohm R. As in all things, it's a trade-off. I think Ralph experimented with a higher value (higher than 1 ohm, that is) and found it was a net plus. I have not messed around with this mod personally, so I have no cogent comment other than stated.
Yes 1ohm did nothing. the plat is 200ohm 1r2 more ohm nt.my kit had no feedback on plats but makes BIG DIFFin sound' an may make the 5.5 5w do it best. IT NOT A SMALL THING 1k on +/+ FEEDBACK.MAY MAKE circlotron work better.big deep bass.more input from uguyes thanks T.V. PS 1K 5/10W
Hi,My Atma-Sphere M-60's started out with 1 ohm 3W plate resistors when I built them as a kit. I tended to lose the plate resistors when a tube blew, so I upped the wattage to 5W. No more blown resistors when a tube died. When Ralph told me about the cathode resistors, I removed the plate resistors and installed 5 ohm 5W resistors (Dale wirewound in my case) on the cathodes. Improved sonics to my ears, and I haven't lost a single tube in nearly a year.
I don't understand how to add a picture on this forum, but I would be happy to send a picture of my amp underside. Just contact me and I will email it to you--
Thanks m8 - I dont know how to do the pic thing either - I think its locked out to stop general rubbish cluttering the site ( fair enough too ! ) . I'll send you a pic or too of mine aswell .
satellites (AT) orcon (dot) net (dot) nz
Thanks for the reply - Stu ( new zealand )
| ||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: