Help with plate chokes - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 18th August 2003, 03:30 PM   #11
eduard is offline eduard  Netherlands
diyAudio Member
 
Join Date: Sep 2002
Location: Holland
Send a message via Yahoo to eduard
Frank, This looks allmost like the line-amp i am using which did win a contest in the Japanese MJ magazine. Only 390 Ohm is 300 ohm and 100 mf is 220 Mf. Sounds very good but the Tango permalloy output is a lot more expensive then a power supply choke! Ed
P.s. Frank you surely remember the thread about the tension on the chassis. The 220 volt outlet will show a light on both sides so something is not 100 % in the very old electrical system.
  Reply With Quote
Old 18th August 2003, 03:47 PM   #12
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

Quote:
Frank, This looks allmost like the line-amp i am using which did win a contest in the Japanese MJ magazine.
Hmmm, I had no idea.

Actually the xformer I had in mind for this cicrcuit is a Bartolucci type D.

BARTOLUCCI.

No idea about the price but expect something around 125 Euro/ea.
A good audio choke probably costs just as much and you still have to capcouple the output at the higher Zo anode side...

Quote:
The 220 volt outlet will show a light on both sides so something is not 100 % in the very old electrical system.
Probably 115-0-115?
That still doesn't explain the leakage current on the chassis the amp though.


Cheers,
__________________
Frank
  Reply With Quote
Old 18th August 2003, 10:06 PM   #13
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

As has been suggested before, the Hammond chokes weren't meant for this kind of service but...if the B+ is lowered then it would take more current through it.

This should lessen the ringing as the circuit draws 8ma already which is these chokes practical limit.

May be worth to try out?

Cheers,
__________________
Frank
  Reply With Quote
Old 18th August 2003, 10:10 PM   #14
diyAudio Member
 
Join Date: Nov 2002
analog_sa

Yes I did check the voltages and did see that with the choke I had a higher plate voltage. I did some swapping of the VR tubes(a 90 and a 75) and I ended up real close to what I had with the plate resistors. I believe I was around 140-144 on the plate with the VR150 and VR90. I think I ended up with around 130 something for the choke test. I was trying to come as close as I could.

Frank

Which way do I go now? Do I pop for some Bartolucci (D) transformers or some Lundahl LL1668 chokes?

Bandersnatch and Frank

I have set the chassis up for two VR tubes and I have enough of them to give me different combinations of voltage. The question is do I complicate things a little more and add another set of VR tubes so that each channel has its own regulated supply? Or...do I go one step further and have a separate transformers and such for each channel?

Who sells Bartolucci in the US.?

Joe
  Reply With Quote
Old 18th August 2003, 10:48 PM   #15
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

Quote:
Which way do I go now? Do I pop for some Bartolucci (D) transformers or some Lundahl LL1668 chokes?
I'd go with the Bartolucci with my eyes closed, it offers nothing but advantages.

They don't have a distributor in the U.S. but don't let that stop you.

If it were me I'd use a dual mono PSU with not just VR tubes but a fully regulated supply per channel.

I wouldn't use a volpot either, a switched attenuator will always be better...then again not all atenuators do sound alike...
There's just no end to it, is there?

Cheers,
__________________
Frank
  Reply With Quote
Old 20th August 2003, 02:31 PM   #16
JBasham is offline JBasham  United States
diyAudio Member
 
Join Date: Apr 2003
Location: At Home
I don't know how to fix your ringing. But, regarding the insinuation that you were stupid to try Hammond PS chokes in another application, I have to rise to that bait. I've used Hammond and Magnetek PS filter chokes to load the plate of 2A3s and it sounded great. Hundreds of other tube addicts agree with me (all the Bottlehead Paramour owners out there). Yes, you get better sound if you spend more on chokes specifically designed for the intended duty, but you don't necessarily get crap if you use a PS choke sometimes.
__________________
The only true thing in audio is what you hear with your own ears.
  Reply With Quote
Old 20th August 2003, 02:35 PM   #17
Fuling is offline Fuling  Sweden
diyAudio Member
 
Join Date: Aug 2001
Location: Sweden (Mora)
I agree.
I use hammond PSU chokes as plate chokes in both my 12B4A Monkey and my 6B4G SE and they both sounds just great!
  Reply With Quote
Old 21st August 2003, 12:27 AM   #18
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

Quote:
Yes, you get better sound if you spend more on chokes specifically designed for the intended duty, but you don't necessarily get crap if you use a PS choke sometimes.
The operative word here is "sometimes".

Sure, we can make this choke work...under the current circumstances it won't.

It's not that hard to figure out why either...

Quote:
I use hammond PSU chokes as plate chokes in both my 12B4A Monkey and my 6B4G SE and they both sounds just great!
And you never wondered what it could sound like with proper audio chokes?

These won't come cheap. Which is why I suggested the OPT as a better alternative; it does away with the cap and solves Zo problems, all in one go.

Cheers,
__________________
Frank
  Reply With Quote
Old 21st August 2003, 12:50 AM   #19
diyAudio Member
 
Join Date: Nov 2002
J Basham

Quote

I don't know how to fix your ringing. But, regarding the insinuation that you were stupid to try Hammond PS chokes in another application, I have to rise to that bait.

J

First of all I wasn't trying to bait anyone. I set up a test situation where the plate voltage and the current draw were within reasonable bounds. Unfortunately the PS choke didn't work in this situation. I was told by one of the most competent members of this board that the usage of this choke probably wouldn't provide the best results. I had my doubts so I tried the choke and posted of my results. Now, if you built this preamp and used this choke with remarkable results then I would surely be interested in all your findings, diagrams, and little tricks to make it work.
Until then my opinion will most certainly remain unchanged.

I have not had personal experience with the Bottlehead. I am under the impression from what I have read that it is a borderline entry level kit. Most people seem to be content with its sonic value and I'm sure it has made its company a great deal of money. If I had wanted to jump on the bandwagon I probably would also have purchased this kit.

However, I have always been more content with something a little different from what most people have. In this case it will end up to be a 5687 line amp with dual regulated supplies and Bartolucci transformers(if they ever answer my email requesting price and delivery).

To imply that I have evidently done something incorrectly kind of irritates me. First of all let us compare apples to apples. You build the same circuit I built and make it work correctly with this cheap $10.00 PS choke. Then you can tell me I am wrong.

Joe
  Reply With Quote
Old 21st August 2003, 01:17 AM   #20
diyAudio Member
 
Join Date: Jul 2003
Location: Ann Arbor, MI
Hey-Hey!!!,
There is a distince polarity regarding chokes, especially ones wound in a single coil. You want to have the end of the coil that was wound against the core to B+, and the end of the coil which has signal to it be the last turns wound. This for plate chokes anyway, I think it makes less diff for PS chokes.
I just wound some center tapped chokes for loading a PP driver stage, similar circuit to one of Brook's. It was wound pie style with each half in a partition on the bobbin form and had in the first version one AC end up against the core. I got a distinct improvement when I wound with both halve's center windings at the core and the AC carrying ends at the outside of the bobbin.
Female vocals were lost the schreeeechy tone, silibance I think it is called, with that single change, same amount of Cu and Iron but change the winding geometry and it was a whole different animal. Makse me scared about the stuff involved with the permutations and combinations involved with OPT's
regards,
Douglas
__________________
the Tnuctipun will return
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
UTC CG-52AX - use as plate chokes? rongon Tubes / Valves 3 22nd August 2009 07:11 AM
Magnequest EXO-99 600H/150H Plate Load Chokes cm7 Swap Meet 6 18th July 2009 01:54 AM
Plate chokes & Power chokes JC951t Tubes / Valves 3 19th October 2006 03:18 PM
Subwoofer Plate Amplifier Base Plate supplier? jwells777 Parts 1 11th May 2003 07:40 AM


New To Site? Need Help?

All times are GMT. The time now is 12:19 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2