JCA OWNERS!!! (RE)JOIN THE JET CITY LOUNGE!!!

[maynardo]

Oh ok recovery it is then, well my contention is that the RC filter is a major key when it comes to string separation, that's why to me, rectos are so undefined (people call them forgiving amps) even when they copied almost all the rest of the Soldano preamp. You can see in the 5150 PV added a fifth gain stage but kept the same rc filter and they're clearer than rectos.

Best Regards

[käsebrot]

[Jay]

Thank you very much Jay for a all the pieces of information!
I hope this will be going on here in the thread.
I'm really happy with the mod I've described and for me there is currently no need to change anything (except the tubes, I could not resist to try several ones).
Oh, and I have swapped out all the non-electric caps and put in blue 2kV ceramics (Vishay BC) and a combination of Sozo and Röderstein caps for the higher values.

Tubes are a sickness! I have spent a lot of time and money playing with all sorts. SO much fun to try them all out. I really need to get around to trying the Roderstein caps. I'm liking what you say about them a lot. A lot of guys over on the Marshall forums also really like them. Next amp I play with will be sure to get some!

[Jay]

Oh ok recovery it is then, well my contention is that the RC filter is a major key when it comes to string separation, that's why to me, rectos are so undefined (people call them forgiving amps) even when they copied almost all the rest of the Soldano preamp. You can see in the 5150 PV added a fifth gain stage but kept the same rc filter and they're clearer than rectos.

Best Regards

There is a lot to the Recto "recipe" that sets it apart from the SLO. The FX loop is a big factor. It's configuration and location is a big factor. The SLO uses more filtering for the power section of the amp to make it a bit tighter and brighter. Also, the two amps have OTs that were designed very specific to help how the amp behaves. The SLO OT is designed to be very Hi-Fi. It has a very wide bandwidth and replicates what the preamp puts out in spectacular fashion. The Recto, on the other hand, has an OT that is designed to be a bit undersized. In this case, it saturates earlier during load, so it sags more, which is part of the Recto 'bark'. The 5150 has a parallel 5th gain stage instead of a cathode follower, and some trickery in the power amp to make the 6L6s behave a bit like EL34s, which I believe, is by biasing the power tubes cold and dissipating more power on the screens. That gives the 5150 that tight, gritty kind of tone.

[racerevlon]

I believe it's been mentioned here before but may bear repeating that the foot switches for the 22H and the 100H/HDM, while looking identical, are NOT compatible.

[Jay]

Really? Have you taken them apart? Wonder what the difference is.

[maynardo]

Oh ok recovery it is then, well my contention is that the RC filter is a major key when it comes to string separation, that's why to me, rectos are so undefined (people call them forgiving amps) even when they copied almost all the rest of the Soldano preamp. You can see in the 5150 PV added a fifth gain stage but kept the same rc filter and they're clearer than rectos.

Best Regards

There is a lot to the Recto "recipe" that sets it apart from the SLO. The FX loop is a big factor. It's configuration and location is a big factor. The SLO uses more filtering for the power section of the amp to make it a bit tighter and brighter. Also, the two amps have OTs that were designed very specific to help how the amp behaves. The SLO OT is designed to be very Hi-Fi. It has a very wide bandwidth and replicates what the preamp puts out in spectacular fashion. The Recto, on the other hand, has an OT that is designed to be a bit undersized. In this case, it saturates earlier during load, so it sags more, which is part of the Recto 'bark'. The 5150 has a parallel 5th gain stage instead of a cathode follower, and some trickery in the power amp to make the 6L6s behave a bit like EL34s, which I believe, is by biasing the power tubes cold and dissipating more power on the screens. That gives the 5150 that tight, gritty kind of tone.

Remember I'm not talking about overall tone, just string separation ... and the 5150 has a fifth gain stage PLUS an anode follower / virtual earth instead of the CF.

Best Regards

[Jay]

Oh ok recovery it is then, well my contention is that the RC filter is a major key when it comes to string separation, that's why to me, rectos are so undefined (people call them forgiving amps) even when they copied almost all the rest of the Soldano preamp. You can see in the 5150 PV added a fifth gain stage but kept the same rc filter and they're clearer than rectos.

Best Regards

There is a lot to the Recto "recipe" that sets it apart from the SLO. The FX loop is a big factor. It's configuration and location is a big factor. The SLO uses more filtering for the power section of the amp to make it a bit tighter and brighter. Also, the two amps have OTs that were designed very specific to help how the amp behaves. The SLO OT is designed to be very Hi-Fi. It has a very wide bandwidth and replicates what the preamp puts out in spectacular fashion. The Recto, on the other hand, has an OT that is designed to be a bit undersized. In this case, it saturates earlier during load, so it sags more, which is part of the Recto 'bark'. The 5150 has a parallel 5th gain stage instead of a cathode follower, and some trickery in the power amp to make the 6L6s behave a bit like EL34s, which I believe, is by biasing the power tubes cold and dissipating more power on the screens. That gives the 5150 that tight, gritty kind of tone.

Remember I'm not talking about overall tone, just string separation ... and the 5150 has a fifth gain stage PLUS an anode follower / virtual earth instead of the CF.

Best Regards

Ooops. Sorry. Got carried away there.

Oh right. I forgot about the VE arrangement.

[maynardo]

If anybody tries referencing to ground the DC heaters in the jca22 please let me know, I still haven't been able to get my hands on one .

[Tortuga]

I love being in the class with the smart kids

[jhall]

I've never been so glad to unload an amp as I was to finally find a buyer for my JCA 2112RC.
I was a poor salesman and had very little good to say about that amp to potential buyers so that
may have factored into how long it took to get rid of after I decided to do so.
Funny thing is that I'm really fighting the temptation to get one of their newer 50 or 100 watt heads.

[Jay]

If anybody tries referencing to ground the DC heaters in the jca22 please let me know, I still haven't been able to get my hands on one .

I may be able to get my hands on one soon. What would you like to know?

[Jay]

I love being in the class with the smart kids

Homework at the end of the week. Study up!

[maynardo]

If anybody tries referencing to ground the DC heaters in the jca22 please let me know, I still haven't been able to get my hands on one .

I may be able to get my hands on one soon. What would you like to know?

The dc heaters aren't regulated in the amp, @mjtripper recorded a clip with how noisy the amp can get , in another board the suggestion of referencing to gnd was made , What I wanna know is if anybody has tried that or gone some other way to eliminate the heater noise.

Best Regards

[Jay]

If anybody tries referencing to ground the DC heaters in the jca22 please let me know, I still haven't been able to get my hands on one .

I may be able to get my hands on one soon. What would you like to know?

The dc heaters aren't regulated in the amp, @mjtripper recorded a clip with how noisy the amp can get , in another board the suggestion of referencing to gnd was made , What I wanna know is if anybody has tried that or gone some other way to eliminate the heater noise.

Best Regards

When I get my hands on one, I'll see if I can try a few things.

[thekopite954]

Hi Guys,

New member & new owner of a JCA50H. Been umming & rrring over getting one of these for months, and finally nabbed on quite cheap, just waiting for it to arrive. Definately seems like a very modifiable amplifier and that's right down my street!

looking forward to getting though

[Tortuga]

Hi Guys,

New member & new owner of a JCA50H. Been umming & rrring over getting one of these for months, and finally nabbed on quite cheap, just waiting for it to arrive. Definately seems like a very modifiable amplifier and that's right down my street!

looking forward to getting though

Heya - glad to see you made it! Great advice in this thread, and awesome people here!

[thekopite954]

That's great, glad to be a part of it! The modding is probably what really made me take that final step and just get one!

If I was 90% sure about getting the head before I found this info, this is where the last 10% came from!

I feel in time, you guys will get sick of the site of my posts :P

[jhall]

Well... after tearing down my JCA 2112RC in this thread. I dumped it and am danmed glad I did.
I have to admit I just got a 2212C and like it a lot. Much better to my ears than the earlier one.
This one is a big improvement in tone. I've heard the loop if finicky but my Eleven Rack or RP1000
should work quite we.. I'd think. I'm hoping to fool around with the RP in four cable to see how that is.
The JCA really doesn't seem to need any assistance in the distortion dept. And this newer one
sounds excellent with the gain up where my older one would just mush out too quick for my liking.
Even the Crunch channel (which is supposed to be the same as the original amps preamp circuit?)
sounds way better to me. This JCA 2212C seems to be the amp everyone was praising in the previous version.
I think this new one and me will be spending a long time together. Still has the stock tubes and all too.

[Jay]

Wow. Was playing the 50H last night on just the Crunch channel with a boost. It's frickin sweet! I really can't explain it, brain gone bye byes right now, but a boosted crunch is really, really nice on these amps. Hmm....

[Promit]

Hey guys, and by "guys" I mean 90% jay for the choke mod on the 22H, why was the Hammond 156M picked? How exact do the specs have to be? I was thinking of getting one of the ClassicTone chokes from Triode instead:
http://store.triodestore.com/ch90ma4hfe.html
But I am not sure which one would be the best choice. I was looking at the 4H Fender at the bottom of the page...

And as long as we're at it, what specs do I need to know if I were to replace the OT? Would an OT from an 18W 1974 type Marshall clone work in the 22? I can't find specs on the JC transformers.

[Jay]

Well, what are you hoping to gain with replacing the OT? It might just be a moot point, and I think you might be able to find better ways to mod the amp more cost effectively for a better end result. If you still want to try a different OT, then I'm sure we can find a good alternative for you. The 22H I have has the specs on all the transformers, so we'll go with that and see what else there is.

The choke you picked should work fine. The Classictone parts are high quality.

[Agradeleous]

Hi folks newbie here and I hope all's well with everyone . I do not know any think about ins and outs so I hope you all will school me LOL . I just ordered the JCA22H and I've seen a ton of info think my head is going to explode . Ihave a question and I'm sorry to say as yet have read this entire thread yet some but not all .
I've read where lot's of folks change the tubes right out the box. I'm wondering if I need to ? Since I trying to jump the gun. I've read where some like the JJ's and yet they seem to have some muddiness to them not sure if i want mud LOL from reading some more I seen where one fella took 12at7 for V1 and 12ax7's in valve 2 and 3 or what ever the third 12ax7 is called . here is the post
------------------------------------------------
"This is an old post but a buddy and I were recently working on tweaking the sound and came across the same issue when trying to get a nice chug without the mud, seems the OD bleeds a bit but the best results came from replacing v1 with something with lower gain like a 12at7 and the rest with JJ 12ax7s which reduced the mud. The headroom seemed a lot more enjoyable to the ear and sat in the mix much better but your results may vary.. Based on some other threads I took the advice to re-bias which made a huge overall change for the better. Hope that helps."
-------------------------------------------------
I spoke with tube depot great folks and they suggest the Ecc81 mullard as the 12at7 or V1 and JJ 12ax7 for the rest power tubes as well
any info would be great . I still have to wait a month though for the head it seems to be back ordered. but I have the cab yaaaaaaay

[Tortuga]

Hi folks newbie here and I hope all's well with everyone . I do not know any think about ins and outs so I hope you all will school me LOL . I just ordered the JCA22H and I've seen a ton of info think my head is going to explode . Ihave a question and I'm sorry to say as yet have read this entire thread yet some but not all .
I've read where lot's of folks change the tubes right out the box. I'm wondering if I need to ? Since I trying to jump the gun. I've read where some like the JJ's and yet they seem to have some muddiness to them not sure if i want mud LOL from reading some more I seen where one fella took 12at7 for V1 and 12ax7's in valve 2 and 3 or what ever the third 12ax7 is called . here is the post
------------------------------------------------
"This is an old post but a buddy and I were recently working on tweaking the sound and came across the same issue when trying to get a nice chug without the mud, seems the OD bleeds a bit but the best results came from replacing v1 with something with lower gain like a 12at7 and the rest with JJ 12ax7s which reduced the mud. The headroom seemed a lot more enjoyable to the ear and sat in the mix much better but your results may vary.. Based on some other threads I took the advice to re-bias which made a huge overall change for the better. Hope that helps."
-------------------------------------------------
I spoke with tube depot great folks and they suggest the Ecc81 mullard as the 12at7 or V1 and JJ 12ax7 for the rest power tubes as well
any info would be great . I still have to wait a month though for the head it seems to be back ordered. but I have the cab yaaaaaaay

Heya! Welcome!

I'm no tube expert, but I'm real happy with the set of JJs I put in my 50H. Not sure what kind of sound you're going for - I usually play blues/rock/hard rock/early metal, and the amp suits me well, especially with the depth mod and voicing switch I did. Just don't judge the amp by the stock tubes, 'cause they're really just there to get you up and running. Make sure you get the bias done, too, as the amps typically come out of the factory cold, so as to save on tube life.

There's been talk about running a Jan Philips 5751 (http://tubedepot.com/nos-5751jan.html) in V1 to reduce gain, which is certainly something I'm after. I'm not sure if CTN ever got one to try out before he moved out of Jet City... I did try an old 12AT7 from my 70's Fender amp, and wasn't liking it too much. I'm sure Jay or somebody will pipe in here, but I think the primary focus needs to be on power tubes, V1, and PI.

Best of luck, and make sure you let us know how you fare.

[Tortuga]

Wow. Was playing the 50H last night on just the Crunch channel with a boost. It's frickin sweet! I really can't explain it, brain gone bye byes right now, but a boosted crunch is really, really nice on these amps. Hmm....

I remember FastRedPonyCar stating that he liked the boosted crunch channel a bit more than the OD channel. I can't wait to get my studio done so I can run the amp up for real so I can try that out.

What boost were you running, Jay, and how was it set up?