Cons for using instrumentation tube PS for project amp... - 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 2nd May 2006, 05:02 PM   #1
2004ex is offline 2004ex  United States
diyAudio Member
 
Join Date: Jun 2004
Location: California
Default Cons for using instrumentation tube PS for project amp...

I have an old Fluke 407 tube regulated power supply (picked up from a fleamarket with very low cost). Contemplating to build a full amp on top of that by expanding the chassis etc., or using it as a dedicated, permanent part of an amp (like the old Williamson with separated PS and amp chassis).The advantage is obvious - no need to build another elaborate PS and redirect the effort and resources to the amp section. It is regulated (claimed to be <0.5% from 0-555V 300mA) +B and grid bias, and turn-key operation as well. What are the cons for such an approach, besides the awkward physical size and the appearance? I recall someone saying that the 0A3/0D3 tubes could be very bad for amps. Any input will be appreciated, before hunting for a hack-saw from the garage.
Thanks.
  Reply With Quote
Old 2nd May 2006, 05:05 PM   #2
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
Eek..Hacksaw?
  Reply With Quote
Old 2nd May 2006, 05:26 PM   #3
2004ex is offline 2004ex  United States
diyAudio Member
 
Join Date: Jun 2004
Location: California
Quote:
Originally posted by DigitalJunkie
Eek..Hacksaw?
Thanks for catching that.
  Reply With Quote
Old 2nd May 2006, 05:58 PM   #4
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
I mean,Why cut it up?
Any particular reason?
  Reply With Quote
Old 2nd May 2006, 08:47 PM   #5
2004ex is offline 2004ex  United States
diyAudio Member
 
Join Date: Jun 2004
Location: California
Quote:
Originally posted by DigitalJunkie
I mean,Why cut it up?
Any particular reason?
What I meant was to start modifying the chassis in order to add the amp section - such as by adding sub-chassis, external extentions etc.
No, I won't cut it up. It is a very nice unit.
  Reply With Quote
Old 2nd May 2006, 08:53 PM   #6
diyAudio Member
 
tubelab.com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
I use lab power supplies for designing tube amplifiers. I get the amp sounding right with a lab supply, then design a power supply that hopefully sounds as good as the lab supply. I currently have 3 lab supplies. A Knight, a PACO, and a Fluke 407D. The Fluke is by far the best of the bunch. Enough juice to melt most tubes.

I have seen good working units go for $200 or more on Ebay. I also bought mine on Ebay for $25. It was listed as surplus, untested. It worked fine. If your unit works good, and looks reasonable, you may be able to sell it for enough to build a good power supply. In fact I have built good amps for $200.
__________________
Too much power is almost enough! Turn it up till it explodes - then back up just a little.
  Reply With Quote
Old 2nd May 2006, 11:47 PM   #7
diyAudio Member
 
Tom Bavis's Avatar
 
Join Date: Jun 2002
Location: Macedon NY
I agree... it's worth much more whole! I bought a 407 at a hamfest for $15, replaced the leaky bumblebee caps and sold it for $175. Actually, after I replaced the caps and readjusted zero volts, it was within a volt at the top and bottom of every range... a FINE piece of electronics.

Design your amp using it, then sell it or use it for the NEXT amp design...
  Reply With Quote
Old 3rd May 2006, 12:30 AM   #8
2004ex is offline 2004ex  United States
diyAudio Member
 
Join Date: Jun 2004
Location: California
Quote:
Originally posted by Tom Bavis
I bought a 407 at a hamfest for $15, replaced the leaky bumblebee caps ... a FINE piece of electronics.

Design your amp using it, then sell it or use it for the NEXT amp design...
I bought the 407 for $7 (without tubes and came with a broken internal multi-switch) in a local flea market. I repaired the switch with epoxy and retubed for about $60 primarily from ebay. Just like what you said, had to replace a leaky bumblebee capacitor (1 uF) and one bad 1% wirewound resistor. It works very well since.

My main questions is, if it is such a good power supply, why not use it directly in audiophile tube amp projects to achieve good results? People have spent lots of money in diy amp parts and why not made use of these vintage equipments? Would that not be better than power supplies in a Marantz 9 or Mcintosh XYZ, which cost big bucks? Some people say that the regulator tubes will bring in unwanted noise to the system. In terms of audiophile (interpret this anyway you want) applications what are the cons?

(PS: I also have a Kepco 815 regulated supply, bigger in size and more expensive ($20 from a local flea market) but fully tubed except for a 5R4GY. That is why I think may be I can use one of them as a
builtup platform for a tube amp for own use).
  Reply With Quote
Old 3rd May 2006, 01:12 AM   #9
diyAudio Member
 
tubelab.com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
Quote:
I bought a 407 at a hamfest for $15, replaced the leaky bumblebee caps and sold it for $175.
I know, I bid on that one, and was sniped in the last few seconds. I later found the one that I currently use. I only blew the dust out of it and plugged it in. I t works, and is currently powering a screen driven 6AV5 P-P test amp that cranks out 80 WPC. That amp needs the 555 volts. It runs close to class B which demands a power supply with a low source impedance.

I usually use the Knight power supply for amp development because it is much smaller. I have used it for development of at least 6 amp designs including the TubelabSE. It takes a good power supply to rival the sound quality that the Knight supply provides.

I have a friend who used an Eico power supply to build a Bugle 45 amp. He then built the power supply for the Bugle 45 using Electra-Print transformers and chokes. He decided that the Eico sounded beter, and he still uses it.
__________________
Too much power is almost enough! Turn it up till it explodes - then back up just a little.
  Reply With Quote
Old 3rd May 2006, 01:40 AM   #10
arnoldc is offline arnoldc  Philippines
diyAudio Member
 
Join Date: Apr 2003
Location: Makati
Send a message via Yahoo to arnoldc
Quote:
I have a friend who used an Eico power supply to build a Bugle 45 amp. He then built the power supply for the Bugle 45 using Electra-Print transformers and chokes. He decided that the Eico sounded beter, and he still uses it.
Because the EICO is regulated? Maybe he should build a regulated power suppl y for the Bugle 45.
  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
Instrumentation Gainclone BWRX Chip Amps 70 16th May 2013 04:59 PM
Ideas 4 final year project in control systems &amp; instrumentation engineering momin Everything Else 0 22nd August 2008 03:04 PM
My OLD Project....... cheap tube audio project!!! tube-lover Tubes / Valves 4 8th May 2008 09:26 PM
M-Audio Delta-44 and instrumentation under Linux suzyj Digital Source 8 27th July 2007 03:43 PM
pros/cons of a chipamp VS a tube amp jarthel Everything Else 2 22nd June 2007 01:18 PM


New To Site? Need Help?

All times are GMT. The time now is 08:14 PM.


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