It is currently Mon Mar 16, 2020 6:21 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next
Author Message
Post subject: J J 's tubes ; a mystery
Posted: Mon Aug 24, 2015 2:19 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
It is about JJ's tubes;

The amp ; Marsahall JCM2000 , 60 watts TSL60
Amp work very well but customer want all new tubes ; JJ's
Order 4 X ECC83S from my dealer ( + 2 X E34L )
About ECC83S:
Only one work fine in the Marshall amp , 3 give a very very low power at speaker outpout .

Try all JJ's on a Fender amp and other home made amp ; work fine !!!
Try many tubes from my stock , different brand on the Marshall ; all work fine
( Groove tubes / Sovteck , chinese , JJ ,Ruby , Tung sol re )

Why 3 / 4 JJ's don't work on the Marshall but are fine on other amps ?


Thank's


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: J J 's tubes ; a mystery
Posted: Mon Aug 24, 2015 8:38 am
Offline
Professional Musician
Professional Musician

Joined: Thu Aug 07, 2014 3:25 pm
Posts: 1023
That's a good one...
The TSL60 uses a rectified circuit for 3 of the tubes. They are connected in an unusual configuration.
http://www.drtube.com/schematics/marsha ... 02%20(2001)%20iss5.pdf
I have found overheated filament rectifiers causing problems before, but this sounds unusual.
Ckeck the soldering and the tube sockets. If you can, measure the filament filter caps.


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Mon Aug 24, 2015 10:15 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
TimsAudio wrote:
That's a good one...
The TSL60 uses a rectified circuit for 3 of the tubes. They are connected in an unusual configuration.
http://www.drtube.com/schematics/marsha ... 02%20(2001)%20iss5.pdf
I have found overheated filament rectifiers causing problems before, but this sounds unusual.
Ckeck the soldering and the tube sockets. If you can, measure the filament filter caps.


I had schematic but your link do not work fort me.
V1 ,V2, V3 heater's use filter caps
V4 and V5 , V6 ( EL34's) no

Bad tubes do not work in anywhere. The only good tube yes .

I will look at these caps and voltages

Thank's


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Mon Aug 24, 2015 11:43 am
Offline
Rock Star
Rock Star

Joined: Wed Apr 11, 2012 7:37 am
Posts: 4099
Location: New York
stratele52 wrote:
your link do not work fort me.

I think this was supposed to be the link:
LINK

_________________
Please subscribe to my Image Channel!
https://www.youtube.com/user/b7567


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Mon Aug 24, 2015 11:46 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Heater voltages;

V1 , V2, V3 ; 5.0 DC 124 millivolts AC = Filtering look OK to me
V4 ; 5.8 AC

I found the heater voltage is low at 5 DC volts for V1 to V3 . These tubes use DC volts
V4 use AC volts at 5.8

That is why the low output power

Look to me that 3 of JJ's ECC83S is less sensitive for heater voltage , one is very sensitive .
Funny all my stock of tubes are more sensitive and customer old tubes also ( Mesa Boogie )
I know tubes need 6.3 volts or not less than 6 volts

the ECC88S might be good , it a bad news for me.

I'm working on power supply now , check everything . It is a hard to work on PCB board amps ……..Need to remove everything .

I'll check power transformer AC volts


Last edited by stratele52 on Mon Aug 24, 2015 11:48 am, edited 1 time in total.

Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Mon Aug 24, 2015 11:48 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
strings10927 wrote:
stratele52 wrote:
your link do not work fort me.

I think this was supposed to be the link:
LINK



Thank's , It is the schematic I have , look to not have the same parts number on PCB board than my amp.


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Mon Aug 24, 2015 1:19 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
stratele52 wrote:
It is about JJ's tubes;

The amp ; Marsahall JCM2000 , 60 watts TSL60
Amp work very well but customer want all new tubes ; JJ's
Order 4 X ECC83S from my dealer ( + 2 X E34L )
About ECC83S:
Only one work fine in the Marshall amp , 3 give a very very low power at speaker outpout .

Try all JJ's on a Fender amp and other home made amp ; work fine !!!
Try many tubes from my stock , different brand on the Marshall ; all work fine
( Groove tubes / Sovteck , chinese , JJ ,Ruby , Tung sol re )

Why 3 / 4 JJ's don't work on the Marshall but are fine on other amps ?


Thank's


DC rectified heater lines are often strung in series. If one of the tube's heaters is defective, all tubes downstream of it will be adversely effected.

Check the VDC off the higher voltage lines. If they are low, could be a PT issue. If they are ok... look at any regulation devices in the DC heater line. Some of the cheaper made solid-state devices can go bad.

Good luck! Keep us posted.


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Mon Aug 24, 2015 3:54 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
All tubes work fine in other amp .

Look to be a bridge rectifier issue . I'll put a new one tomorrow .
In circuit it read wrong resistor , I remove it ; wrong reading too or I damage it with heat !

Thank you all to help me although this is not a Marshall, forum I know there are many experts here and thank you especially to TimsAudio


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Tue Aug 25, 2015 1:34 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
I replace the Bridge rectifier , now heater voltage is good at 6.5 DC volts

Thank's TimsAudio :D


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Tue Aug 25, 2015 1:44 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
Do the new JJ tubes operate correctly now?

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Tue Aug 25, 2015 1:50 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Retroverbial wrote:
Do the new JJ tubes operate correctly now?

Arjay



Yes :D


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Tue Aug 25, 2015 2:21 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
Tres bien!

And kudos to Tim for a great call.

8)

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Tue Aug 25, 2015 3:36 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
+1000 for Tim

I was very surprise about low heater voltage , tubes look glowing fine at my eyes .


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Tue Aug 25, 2015 4:11 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
As we all know, eyes -- and ears -- can be deceiving. Best to take a precision measurement with a meter when in doubt.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: J J 's tubes ; a mystery
Posted: Tue Aug 25, 2015 7:33 pm
Offline
Professional Musician
Professional Musician

Joined: Thu Aug 07, 2014 3:25 pm
Posts: 1023
Hey, I'm glad that worked out. I've seen a few go bad in these Marshalls.
The high ripple current wears out the diode junctions and the forward voltage drop goes up.
Then it gets hot and the solder fails too


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: