Yet another Priboi thread... - 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 15th December 2010, 04:02 AM   #11
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by tchiwam View Post
The GU-19 indeed look like a plug in replacement, anyone here has done the conversion ?

Trouble is I still have a big stock of the 6R3S-1...
So use them while they are alive...

Looks like they took a bulb from Gu-19, and put inside simplified internals from Gu-29.
__________________
"Our youth [...] have bad manners, contempt for authority; they show disrespect for their elders, contradict their parents, [...] and tyrannize their teachers. -- Plato, 447-367 BCE
  Reply With Quote
Old 15th December 2010, 08:16 AM   #12
tchiwam is offline tchiwam  Finland
diyAudio Member
 
Join Date: Sep 2010
Location: Lapland, Finland
I ordered 4 GU-19... Seems that all parameters should at least allow them not to blow when swaped, then again what will be the sound like ???
  Reply With Quote
Old 4th January 2011, 08:05 PM   #13
tchiwam is offline tchiwam  Finland
diyAudio Member
 
Join Date: Sep 2010
Location: Lapland, Finland
Found some GU-29 lamps and sockets... I have enough boards to practice with those and the GU-19...
  Reply With Quote
Old 5th January 2011, 12:12 AM   #14
OAA7 is offline OAA7  Ukraine
diyAudio Member
 
OAA7's Avatar
 
Join Date: Jan 2011
Send a message via Skype™ to OAA7
Quote:
Originally Posted by tchiwam View Post
I ordered 4 GU-19... Seems that all parameters should at least allow them not to blow when swaped, then again what will be the sound like ???
be careful with this tube (gu-19), it's UHF tube, if your amp will transform to uhf generator, you may damage your hf-speaker...
  Reply With Quote
Old 5th January 2011, 01:02 PM   #15
Olrum is offline Olrum  Ukraine
Banned
 
Join Date: May 2009
Location: Crimea.Sevastopol
Modernization, "Priboi" long held in Russia.Iz all options no matter how strange the best were on 6R3s and GU29.
GU-19 is not working properly and the sounds of little use for audio.
EL34 absolutely not suitable for use in this amplifier, as suggested some.
  Reply With Quote
Old 6th January 2011, 05:47 AM   #16
tchiwam is offline tchiwam  Finland
diyAudio Member
 
Join Date: Sep 2010
Location: Lapland, Finland
Quote:
Originally Posted by Olrum View Post
Modernization, "Priboi" long held in Russia.Iz all options no matter how strange the best were on 6R3s and GU29.
GU-19 is not working properly and the sounds of little use for audio.
EL34 absolutely not suitable for use in this amplifier, as suggested some.
Any recommended voltages for the grid ? Or changes to go with the GU-29 ?

I now have both GU-19 and GU-29 on their way home. I know the GU-29 ask for forced air cooling, but I doubt I'll run them to their maximum I don't know what to expect on the power output with the GU-29, these are monsters.
  Reply With Quote
Old 6th January 2011, 06:46 AM   #17
tchiwam is offline tchiwam  Finland
diyAudio Member
 
Join Date: Sep 2010
Location: Lapland, Finland
I was thinking to go as such...

Ua = 420V Would like to keep it like that unless the 75W version 480V tap is somewhere in there...

Ug2 =< 225V, now at 240V
This is the max voltage for that grip so a little change on R21 and R24

Bias =~ -20V
Change R14 and R15 to go from -35V to -20V
  Reply With Quote
Old 21st January 2011, 04:02 PM   #18
diyAudio Member
 
artosalo's Avatar
 
Join Date: Feb 2010
I try to "remotely" locate a problem with one Priboi where the output tubes have been changed to 6550.
The owner has measured only some 20 W output power before clipping occurs.
The screen grid voltage is only 250 V and control grid bias - 24 V. The cathode current is some 65 mA.

Does anybody know what is the nominal impedance or turns ration (to 8 ohms output) of the original output transformer of Priboi ?

Is this conversion (6R3S to 6550) anyhow typical ?
Does it require some modifications to the circuitry ?
  Reply With Quote
Old 21st January 2011, 06:03 PM   #19
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by Olrum View Post
EL34 absolutely not suitable for use in this amplifier, as suggested some.
Let's agree to disagree. I can make a nice amp from Priboy using EL34 tubes.
__________________
"Our youth [...] have bad manners, contempt for authority; they show disrespect for their elders, contradict their parents, [...] and tyrannize their teachers. -- Plato, 447-367 BCE
  Reply With Quote
Old 21st January 2011, 09:45 PM   #20
tchiwam is offline tchiwam  Finland
diyAudio Member
 
Join Date: Sep 2010
Location: Lapland, Finland
Quote:
Originally Posted by artosalo View Post
I try to "remotely" locate a problem with one Priboi where the output tubes have been changed to 6550.
The owner has measured only some 20 W output power before clipping occurs.
The screen grid voltage is only 250 V and control grid bias - 24 V. The cathode current is some 65 mA.

Does anybody know what is the nominal impedance or turns ration (to 8 ohms output) of the original output transformer of Priboi ?

Is this conversion (6R3S to 6550) anyhow typical ?
Does it require some modifications to the circuitry ?

I don't know what are they but I found one priboi transformer drawing with
Primary (A1) 1200 ( +480V ) 1200 ( A2 )
Sec (GND) 105 ( 4ohm ) 25 ( 8ohm )

So I guess it is the number of turns, and this would be 130 turns for 8 ohm on the secondary. I am going to pick up my sig generator some of these days and try to calculate the impedence of the input unless someone else can tell me what it is...

I found out that at least on mine the Anode voltage is +480V ! and not +420V like the schematics seem to indicate.
  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
Priboi tweakers ? Zen Mod Tubes / Valves 4 14th May 2007 08:22 PM
Looking for a thread... tubesdude Tubes / Valves 0 5th October 2005 04:25 AM
new thread yariv Forum Problems 1 6th July 2005 10:11 PM


New To Site? Need Help?

All times are GMT. The time now is 05:50 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