Divided by 13 JRT 9/15 - Tube Help

[flashPUNK]

I'm going to be taking shipment for a Divided by 13 JRT 9/15 tonight. This amp is used, and I know that the tubes haven't been changed for about 2 years.

I'm going to be re tubing it shortly - But I can't seem to find what tubes it requires - there isn't any info on the %13 site.

Also, has anyone had any good luck finding some decent combinations of tubes to use with this amp?

Thanks a ton!

[blues junkie]

Call Fred, he can answer all you questions.

Cograte on the amp.

[flashPUNK]

Yeah, I saw that listed on his site - maybe i'll give him a call and see what he says, but if theres anyone with suggestions as to what tubes I could try with it to get the maximum sound of of this thing, i'd appreciate it.

I'll be playing it through a /13 2x12D cab for larger gigs, and a DrZ 1x12 w/Celestion Blue for smaller ones, and rehearsals.

[Southern ILL]

If'n its gots teh original tubes Fred loaded up in it and theres nothing wrong with them(2 years ain't nothing) I'd play the thing first and enjoy it......they are great amps....Fred gets it right outa the shop.

[ski_fast]

The output tubes are probably fine. If it has newer preamp tubes I would look for old RCA, GE, Tung-sol, Amperex, Mullard. Then mix them up, don't run all one brand. It will give you a fatter tone. If you want lower gain put a 5751 in the first position. For newer EL84's the JJ's sound great. I run those in my Supreme 16. I would like to try the TAD's. They are a little bigger so make sure they fit.

[flashPUNK]

I'm not even sure if it uses 12AX7?

i've tried a 5751 in a Pro Jr before - with great results.... Good suggestion, i'll definitely try that out.

[theirflowers21]

it uses, two 5879 pentode pres, one 12ax7. 2 el84s, 2 6v6s, and a gz34 rectifier. Hope that helps.

[flashPUNK]

Originally Posted by theirflowers21

it uses, two 5879 pentode pres, one 12ax7. 2 el84s, 2 6v6s, and a gz34 rectifier. Hope that helps.

Thank you!


Now - since there is only one preamp tube, would it be dangerous to try a 5751?

[flashPUNK]

Also, i've never had to buy 5879 Pentode tubes. Any tips for that? suggestions?

[theirflowers21]

Ah, the 5879 tubes are part of the preamp, they are just a different type of tube than a 12ax7. You could use a 5751 in place of the 12ax7, which is the phase inverter of this amp. You cannot interchange with the 5879 tubes. You can get those from many of the tube dealers here, I've seen them at www.kcanostubes.com, he is a member here and a really good dealer of tubes.

[theirflowers21]

I believe they are not currently being made, buy there are lots of nos tubes available.

[flashPUNK]

Ok, that makes sense - i apologize for any dumb q'ns, i'm learning about tubes/etc. I know what is good (RCA,Mullard,GE), but the specifics of it allude me.

Now, i'm wondering if the 5879 tube is in the V1 spot, and the 12ax7 is in V2... I know that when I had my Pro Jr and tried the 5751 in V2, it didn't have very good results.

[flashPUNK]

i've got a great source for tubes locally (Canada) http://www.thetubestore.com

[theirflowers21]

In this amp, each 5879 is controlled by its own volume control. The amp is laid out with a cut knob, 5 position tone switch, then 2 volumes. Each of the volumes are voiced differently, allowing you to blend each. Does that make anysense? Im bad at explaining but I'm tryin

[flashPUNK]

Originally Posted by theirflowers21

In this amp, each 5879 is controlled by its own volume control. The amp is laid out with a cut knob, 5 position tone switch, then 2 volumes. Each of the volumes are voiced differently, allowing you to blend each. Does that make anysense? Im bad at explaining but I'm tryin

I understand completely.

The previous owner told me that the two volumes weren't blend-able though. I won't know for sure till later on today.