Jolida.....It deaded! Tube help please!

BaggedLancer

So I turn on the Jolida for the morning warm up....2 minutes later....BANG. The fuse in the back burst. Wtf I say, so before I even just go replace the fuse I make a call to Jolida and have them walk me through what could cause it first.

It ended up being the V7 output tube was no good, which I had a feeling it was on the way out the door by the way it was biasing. The Jolida tech was friendly, we ran through it quick, and he recommended that I replace all 4 at the same time.

So now comes the question, I can use 6550, KT88, or EL34. Which do you guys recommend? I hear Mullard is good but way out of my price range, I'm not even sure if I can afford 4 of anything right now cause this was a VERY unexpected expense.

I'm thinking about the JJ Tesla EL34's, what do you guys think?

Thanks in advance.

AndyGwis

what do you guys think?

I think I'm happy to have ss

Between cleaning vinyl and rolling tubes, I don't see how some of you guys even have time to listen to the music.

If I had the dough, I would get the MF KW whatever that is an integrated with universal CD player. $9K new, though, $5K used. . . but would make life so much easier.

Good luck with your tubage.

Systems

I'm using Tung Sol 6550 and Genelax Gold Lion KT88 in my Jolida. I think these sounded the best. The Tung Sols can be had for around $108 for a quad and the Genalex go for around $180 a set. Jolida recommends running the KT88's at a slightly lower voltage than the 6550's. My bias setting is between 45mv and 55mv. I set the KT88's at about 47mv. Works good for me.

mhardy6647

So now comes the question, I can use 6550, KT88, or EL84. Which do you guys recommend? I hear Mullard is good but way out of my price range, I'm not even sure if I can afford 4 of anything right now cause this was a VERY unexpected expense.

I'm thinking about the JJ Tesla EL84's, what do you guys think?

EL34s... you can use EL34s not EL84s.

The problem you had is the risk of using new production tubes. They just are not as robustly-made (or, at least as carefully QC'd) as they were in the Good Old Days.

That said, cost-wise, you probably have no real choice but new production (unless you buy used old tubes, which can be a good deal but matching would be a challenge). I cannot recommend any new 6L6-family tubes (which is what the EL34, 6550, KT88, etc. all descend from) as I have no experience with any of them.

Always keep a spare box of fuses, and be glad that the fuse blew instead of losing an output transformer when the output tube shorted. Is it a fixed bias amp? Do you know the screen and plate voltages JoLida uses in that amp? The new tubes tend to be very fragile at or beyond the "book value" max parameters, while the old tubes were more forgiving. Perhaps the JoLida can be biased down a bit; I dunno. I am sure folks here or on other audio boards do, though.

The least-economical but lowest-risk bet is to buy a vintage McIntosh tube amp such an an MC-225. Most Mac amps ran the tubes so conservatively that they'll last virtually forever.

RuSsMaN

You can't use EL84, EL34 sure, 84, no.

I prefer 6550's out of the 3. The re-issue TungSol's are solid.

madmax

Out of all the tubes I tried I thought the Tung Sol 6550's sounded the best. You have the 502A Jolida? I think you meant EL34 tubes rather than EL84. I'm not sure the EL34 is a direct replacement or not. May need a resistor added?

wingnut4772

AndyGwis wrote: »

I think I'm happy to have ss

Between cleaning vinyl and rolling tubes, I don't see how some of you guys even have time to listen to the music.



Good luck with your tubage.

Me too!

Good luck. Hope you fix it.

Ricardo

Tung-Sol 6550's were my choice too on the TAD-60's that visited for a while. Very nice low end.

marvda1

the 502 does not use el34's, only 6550 and kt88.

BaggedLancer

mhardy6647 wrote: »

EL34s... you can use EL34s not EL84s.

The problem you had is the risk of using new production tubes. They just are not as robustly-made (or, at least as carefully QC'd) as they were in the Good Old Days.

That said, cost-wise, you probably have no real choice but new production (unless you buy used old tubes, which can be a good deal but matching would be a challenge). I cannot recommend any new 6L6-family tubes (which is what the EL34, 6550, KT88, etc. all descend from) as I have no experience with any of them.

Always keep a spare box of fuses, and be glad that the fuse blew instead of losing an output transformer when the output tube shorted. Is it a fixed bias amp? Do you know the screen and plate voltages JoLida uses in that amp? The new tubes tend to be very fragile at or beyond the "book value" max parameters, while the old tubes were more forgiving. Perhaps the JoLida can be biased down a bit; I dunno. I am sure folks here or on other audio boards do, though.

The least-economical but lowest-risk bet is to buy a vintage McIntosh tube amp such an an MC-225. Most Mac amps ran the tubes so conservatively that they'll last virtually forever.

Edited my post for the EL34, which is what I meant, not the 84.

Amp is a 502B withe Jolida EZ Bias, so I assume I can bias it down to what it needs to run new tubes.

marvda1 wrote: »

the 502 does not use el34's, only 6550 and kt88.

Why would that be the case if all the tubes are in the same family? Doesn't make any sense.




Any good places to get the Tung Sol from? I'd like to grab a matched quad.

analog97

Bagged:

Next time you get the tech guy from Jolida on the phone, ask him how the Jolida phono pre-amp puts out 95db gain!!

mhardy6647

Look at the data for the three tube types:
http://tdsl.duncanamps.com/tubesearch.php

KT88 and 6550 are rated for 40 watts plate dissipation; EL34 only ca. 25 watts
Max. screen voltage is lower for EL34, too.

http://www.mclink.it/com/audiomatica/tubes/6550.htm
http://www.mclink.it/com/audiomatica/tubes/kt88.htm
http://www.wps.com/archives/tube-datasheets/Datasheets/Amperex-HF656/6.JPG

Tube trivia quiz: Do you know what the "KT" stands for in "KT-88"? :-)

cfrizz

Me 3!:) And don't forget about having to let the tubes warm up.

AndyGwis wrote: »

I think I'm happy to have ss

Between cleaning vinyl and rolling tubes, I don't see how some of you guys even have time to listen to the music.

Good luck with your tubage.

RuSsMaN

mhardy6647 wrote: »

Look at the data for the three tube types:
http://tdsl.duncanamps.com/tubesearch.php

KT88 and 6550 are rated for 40 watts plate dissipation; EL34 only ca. 25 watts
Max. screen voltage is lower for EL34, too.

http://www.mclink.it/com/audiomatica/tubes/6550.htm
http://www.mclink.it/com/audiomatica/tubes/kt88.htm
http://www.wps.com/archives/tube-datasheets/Datasheets/Amperex-HF656/6.JPG

Tube trivia quiz: Do you know what the "KT" stands for in "KT-88"? :-)

Plate dissapation doesn't matter, they can all do 800v on the plate, the heaters are identical electrically.

Early B.

If you're strapped for cash, just replace the bad tube and pop a new Rat Shack fuse in.

Always keep spare tubes and fuses, especially for the Jolida.

BaggedLancer

Problem if I do it that way Early B is that if I do that I know I half assed it and I will be biased and say it doesn't sound as good and it definately doesn't sound better. I'm strapped for cash till my tax checks come...that's all. I probably will end up with a matched quad of Tung Sol reissues, they seem cheap enough.

madmax

BaggedLancer wrote: »

Problem if I do it that way Early B is that if I do that I know I half assed it and I will be biased and say it doesn't sound as good and it definately doesn't sound better.

You have to learn to trust your ears.

Oh, BTW, the Tung Sols sound like **** for the first 50 hours or so. Way worse than most other tubes. They get much better though.
madmax

BaggedLancer

I'm listening to my music on my home theater right and I'm ready to pull my hair out. In terms of the **** scale, I've had **** that sound better than this.

It's either these:
http://cgi.ebay.com/Tung-Sol-6550-Factory-Matched-Quad_W0QQitemZ160195938788QQihZ006QQcategoryZ64629QQrdZ1QQssPageNameZWD1VQQtrksidZp1638.m118.l1247QQcmdZViewItem

or

http://cgi.ebay.com/Genalex-Gold-Lion-KT88-Matched-Quad-Free-Shipping_W0QQitemZ160195938384QQihZ006QQcategoryZ64629QQcmdZViewItem (if the guy will negotiate with me)

mhardy6647

Plate dissapation doesn't matter, they can all do 800v on the plate

Plate dissipation is about power, not potential, so plate current does matter, as does (might) the potential on the screen grid. I don't know either parameter on the JoLida, so I dunno. EDIT: So why can't they use EL34s in the JoLida, Russ?

EDIT^2: for those who might want to know why a KT is called a KT...
For those who don't know what a KT is...
http://en.wikipedia.org/wiki/Beam_tetrode

Ricardo

BaggedLancer wrote: »

I'm listening to my music on my home theater right and I'm ready to pull my hair out. In terms of the **** scale, I've had **** that sound better than this.

It's either these:
http://cgi.ebay.com/Tung-Sol-6550-Factory-Matched-Quad_W0QQitemZ160195938788QQihZ006QQcategoryZ64629QQrdZ1QQssPageNameZWD1VQQtrksidZp1638.m118.l1247QQcmdZViewItem

or

http://cgi.ebay.com/Genalex-Gold-Lion-KT88-Matched-Quad-Free-Shipping_W0QQitemZ160195938384QQihZ006QQcategoryZ64629QQcmdZViewItem (if the guy will negotiate with me)

These might be a bit more expensive, but I've had great service from these guys. Not sure you'll get the same from an ebay seller

http://thetubestore.com/tungsol6550.html

BaggedLancer

So I'm going to order some tubes right now and it's asking me if I want early, average, or late distortion, anyone care to explain that to me?

Ricardo

Where are you ordering?

Early B.

BaggedLancer wrote: »

I'm listening to my music on my home theater right and I'm ready to pull my hair out. In terms of the **** scale, I've had **** that sound better than this.

:D:eek::D:D

wingnut4772

cfrizz wrote: »

Me 3!:) And don't forget about having to let the tubes warm up.

Cathy, I think this will be the one thing I hold out on with you.:)

BaggedLancer

Just ordered a matched quad of Tung Sol 6550 for $125 shipped and insured from Doug's Tubes in NY. Found his site through audiokarma, talked to him on the phone, seemed like a really nice, and went ahead and placed the order.. Should be here by Saturday/Monday.

Listening through my music through my home theater is like someone running fingernails down a chalkboard.....

marvda1

baggedlancer, where did you get that the el34 and 6550 are in the same family?
per bioworks here are the two families:
1) 6550/kt88/kt90/kt100
2) el34/6ca7/kt77
the jolida 302b is the el34 based version of the 502b

Early B.

marvda1 wrote: »

baggedlancer, where did you get that the el34 and 6550 are in the same family?
per bioworks here are the two families:
1) 6550/kt88/kt90/kt100
2) el34/6ca7/kt77
the jolida 302b is the el34 based version of the 502b

The 502 can be easily modded to accomodate both the el34 tubes and 6550 family of tubes. The difference between the 302 and 502 is basically a couple of resistors.

marvda1

early b, only if the 502b does not have the ez-bias, per bill baker at response audio.

mhardy6647

They all descend from the 6L6 beam power tube, although as has been amply pointed out, they are not all interchangeable in any given circuit. The 6V6 is also closely related, believe it or not.

http://en.wikipedia.org/wiki/6L6
http://en.wikipedia.org/wiki/EL34

Early B.

marvda1 wrote: »

early b, only if the 502b does not have the ez-bias, per bill baker at response audio.

Oh yeah, I forgot about the "new" Jolidas. They've gotten fancy lately. Great amps for the money, though. Madmax is the resident expert on these units.

madmax

Early B. wrote: »

Oh yeah, I forgot about the "new" Jolidas. They've gotten fancy lately. Great amps for the money, though. Madmax is the resident expert on these units.

Not me although I know my way around on the older units (the A versions).

Oh yeah, on the early/mid/late distortion thing. This is a guitar amp/musical instrument thing. For Hi Fi usage you want the late distortion if someone is picking them that way. This is just a description of where they start distorting in the power band. Early means they distort quite easily.

madmax