Dyna ST70 PWR Tranny 6.3V Crnt Spec? - 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 8th July 2008, 05:22 AM   #1
kegger is offline kegger  United States
diyAudio Member
 
Join Date: May 2004
Location: michigan
Default Dyna ST70 PWR Tranny 6.3V Crnt Spec?

Anybody seen/know what the 6.3v windings on the Dyna 70's current ratings are by chance. (original)

I mean we obviously have 3a for both EL34, then .45a for a 7199 plus the pre socket out front on each side.

So what 4a, 4.5a?
  Reply With Quote
Old 8th July 2008, 05:41 AM   #2
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
The manual says that it can supply up to 1A at 6.3V to each preamp socket. So that's ~4.45A per channel.
  Reply With Quote
Old 8th July 2008, 05:53 AM   #3
kegger is offline kegger  United States
diyAudio Member
 
Join Date: May 2004
Location: michigan
Thank you kind Sir!

As I'm looking to use 4.2a per side on the 6.3v windings and not use the 5v winding at all.

I was hoping my plan has a chance to work and sounds as if it just may.
  Reply With Quote
Old 8th July 2008, 05:55 AM   #4
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
Yea,That should work nicely.
  Reply With Quote
Old 8th July 2008, 06:09 AM   #5
diyAudio Member
 
Join Date: May 2005
Location: California
Original Dynaco said that it could provide the extra 1 amp per winding but this was an exaggeration. Current through the outputs was also exaggerated in their specs, realistic numbers are 40ma per EL34.
A realistic value for each 6.3volt winding is 3-3.5 amps tops.
Daniel

Edit: I just saw that you won't be using the 5 volt winding, so this will give you some extra elsewhere in the transformer. Try your circuit out and see how hot the transformer gets. If it's too hot to put your hand on it, I would ease off a little. You can always put a small filament transformer under the chasis.
  Reply With Quote
Old 8th July 2008, 06:14 AM   #6
kegger is offline kegger  United States
diyAudio Member
 
Join Date: May 2004
Location: michigan
Humm, in stock form with nothing plugged into the front your running 3.45ma all the time.

I know the power tranny's in 70's run hot but I've still yet to see a dead one. (yet that is)

Was hoping that not running anything off the 5v winding may help some as well. (yah you saw it)

We'll see how it goes.

Thanks,
keg
  Reply With Quote
Old 8th July 2008, 06:22 PM   #7
diyAudio Member
 
MQracing's Avatar
 
Join Date: Oct 2005
Hi Kegger:

From the orig factory blueprints each of the two separate 6.3vct windings are rated at 4 Arms.



MSL
  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
Dyna PAM preamp Mark Korda Swap Meet 0 4th August 2009 11:33 PM
FS: Dyna PAT-4 Preamp al2002 Swap Meet 1 8th January 2009 05:00 PM
Dyna Pas 3X? Thatch_Ear Tubes / Valves 17 16th January 2008 06:10 PM
Dyna ST70 experience bypassing input tubes tubesmuggler Tubes / Valves 12 20th August 2006 05:54 AM
DIY Dyna MK 2's and using bottlehead C4S freddymac406 Tubes / Valves 7 18th April 2005 11:45 PM


New To Site? Need Help?

All times are GMT. The time now is 06:03 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