Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

Tube HW question from a software guy
Tube HW question from a software guy
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
Thread Tools Search this Thread
Old 9th May 2006, 06:59 AM   #1
rgoodnight is offline rgoodnight  United States
diyAudio Member
Join Date: May 2006
Default Tube HW question from a software guy

I have a piece of tube equipment (a Bellari vp129 tube phone stage) that came equipped with a 12VAC - 600mA power supply (i.e. wall wart). The spec says that the unit can take 12-18VAC.

I misplaced the power supply during a move. I cannot find a replacement supply with the exact specs (and don't want to wait weeks and spend $40 for a replacement from the manufacturer) and I have some questions about using power supplies with a higher voltage rating (but still within the 12-18VAC in the spec).

I assume that the spec indicates that I cannot "fry" the unit by having up to 18V instead of the 12V. I don't know enough about tubes or the architecture of the Bellari, but I have to believe that powering with, say 16V, instead of 12V will change its sonic characteristics quite dramatically.

Question 1) What is the impact of the supply voltage on the sonics/performance of tube gear?

Question 2) Can I simply put a resistor in series to drop the voltage of my 16V replacement power supply to 12V, or is that going to affect the quality of the power and affect the performance of the tube unit.

Question 3) Am I going to do any damage to the Bellari by trying different power supplies and voltage ranges as long as they are within the specs? This way I can use my ears to judge.


Randy (who remembers when we didn't worry about power conditioners, power cords, etc.)
rgoodnight is online now Reply With Quote
  Reply With Quote
Old 9th May 2006, 08:42 AM   #2
SHiFTY is offline SHiFTY  New Zealand
diyAudio Member
SHiFTY's Avatar
Join Date: Jul 2002
Location: New Zealand
If it's in the specifications it should be fine.

Just make sure that your power supply is rated for 600mA or more.

It's too hard to say what difference it will make- you need a schematic for that.
  Reply With Quote
Old 9th May 2006, 09:01 AM   #3
dsavitsk is offline dsavitsk  United States
diyAudio Member
dsavitsk's Avatar
Join Date: Jan 2005
Location: Hartford
I would guess there are voltage regulators in there that take whatever you give it and turn it into what it wants. So, a higher voltage PS probably will not influence the sound at all. However, since the tube's heater draws 300mA at 6.3V (likly the largest draw in the amp), and a voltage regulator needs to drop from the input voltage to 6.3V, as the PS creeps higher, the voltage regs will need to dissipate a lot more heat -- almost 2 extra watts moving from 12 to 18V. Probably not a huge deal, but worth being aware of and probably giving it some extra ventilation.
  Reply With Quote


Tube HW question from a software guyHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tube design software arvin Tubes / Valves 8 7th March 2007 07:01 PM
What is the best software to create tube schematic mario2005 Tubes / Valves 16 18th July 2006 01:09 AM
tube software karma Tubes / Valves 3 24th May 2005 11:07 PM
Looking for tube design software. NotInTheMafia Tubes / Valves 5 25th October 2003 01:52 PM
Pcb software for tube designs ashok Tubes / Valves 15 29th August 2002 08:37 PM

New To Site? Need Help?

All times are GMT. The time now is 07:58 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio