Guitar Gear Forum

Jay wrote:The 22H is pretty responsive to tube changes. I have not modded this one yet, but I can tell you that I do NOT like the JJ ECC83s in it. The 803s is good in V5, but that's it. It DOES like a good selection of a few choice 60s tube I have hanging around. 60s Mullard I have and RCA grey plates sound FANTASTIC in V1. Just used some Penta Chinese tubes in V2-V4 and some other oddball tubes in the PI and the tones are so much better to me. I've really been gelling more with the crunch channel with a boost than just the OD channel.

I love RCAs , a guy I know calls those things 'Jimmy Hendrix in a box'

If you do the clean/crunch and srv switches/mods on the 22 can you record a small demo of their effect ? ... it's a lot easier to convince people of a mod when there's some youtube video showing them.

Best regards

While I may not be doing those particular mods, I'll try and do a clip when I get it ironed out.

Jay wrote:The 22H is pretty responsive to tube changes. I have not modded this one yet, but I can tell you that I do NOT like the JJ ECC83s in it. The 803s is good in V5, but that's it.

I've been happy with a TungSol in V1 and JJ in V2. The JJ gives the OD channel a slightly darker and thicker tone, which I like since the amp is fairly bright. A Mullard might be better still, and I'm reasonably certain any halfway decent NOS tube would be far and away a better choice, but ah well.

I just saw this http://www.ampfactory.com/22h-custom/ that vertical 2x12 just killed me & really liked all the options they offer for the 22

Anybody else get one of the picovalves being closed out? Just wondered of all the latest mods. This is what I have done so far. The component names are from the pcb and not the schematic. Images plus before/after clips attached.

r2=10k
remove c1
add 680pf on v1 between pins 2 and 3
r3=150k
r5=1.8k bypassed with 1uf
c2=4.7nf followed by 470k paralleled with 470pf
remove c3
c7=470pf
r9=1.8k bypassed with 1uf
c5=10nf
r14=470k
c13=470pf
add 1M on v2 between pin 2 and ground
bypass r26 with 1000pf



https://soundcloud.com/mjtripper/picovalve-before-mods

https://soundcloud.com/mjtripper/picovalve-after-mods

I just got mine. I like it stock so far. I'm going to try to play it for a while before I make any changes.

Wayne wrote:I just got mine. I like it stock so far. I'm going to try to play it for a while before I make any changes.

You might want to make the below change at least as it looks like a production error of some sort. What was supposed to be the grid leak resistor was instead used as part of what is normally a treble peaking setup and controlled with the bright switch but the grid leak was then omitted. This is in the schematic but missing from the amp, or at least from the one I got. The bright switch and needed resistor was missing from the schematic also and it looks like they just used that 1m but moved it. There were a few other values in the schematic I found that were wrong but the part type and placements were correct.

add 1M on v2 between pin 2 and ground

mjtripper wrote:

Wayne wrote:I just got mine. I like it stock so far. I'm going to try to play it for a while before I make any changes.

You might want to make the below change at least as it looks like a production error of some sort. What was supposed to be the grid leak resistor was instead used as part of what is normally a treble peaking setup and controlled with the bright switch but the grid leak was then omitted. This is in the schematic but missing from the amp, or at least from the one I got. The bright switch and needed resistor was missing from the schematic also and it looks like they just used that 1m but moved it. There were a few other values in the schematic I found that were wrong but the part type and placements were correct.

add 1M on v2 between pin 2 and ground

so it's defective? crap. I'd better register the warranty.

Wayne wrote:

mjtripper wrote:

Wayne wrote:I just got mine. I like it stock so far. I'm going to try to play it for a while before I make any changes.

You might want to make the below change at least as it looks like a production error of some sort. What was supposed to be the grid leak resistor was instead used as part of what is normally a treble peaking setup and controlled with the bright switch but the grid leak was then omitted. This is in the schematic but missing from the amp, or at least from the one I got. The bright switch and needed resistor was missing from the schematic also and it looks like they just used that 1m but moved it. There were a few other values in the schematic I found that were wrong but the part type and placements were correct.

add 1M on v2 between pin 2 and ground

so it's defective? crap. I'd better register the warranty.

It's not really defective since it will work this way but I would call it a design flaw It's based on the thd univalve which doesn't have the bright switch but does have that 1m grid leak. A marshall would have a 470k grid leak there instead of the 1m.

So a friend of mine was asked to mod a jca22h with the SLO and depth mods, this were his results

[video]https://www.youtube.com/watch?v=UdbFOj8bcqM[/video]

The depth knob it's on the back of the amp and the SLO mod included the 500k gain pot.

Best regards

maynardo wrote:So a friend of mine was asked to mod a jca22h with the SLO and depth mods, this were his results

[video]https://www.youtube.com/watch?v=UdbFOj8bcqM[/video]

The depth knob it's on the back of the amp and the SLO mod included the 500k gain pot.

Best regards

Sounds great, man! Someday I gotta look into the SLO mods. Thing is, I'm still really happy with the simple voicing mod I did several months ago. Maybe when I get my studio up and running, I'll finally be able to give it a better run-through and see if I want to do anything more.

...by the way, Maynardo - I haven't forgotten about the clips. I've been slammed with getting my studio done, and haven't been able to get my gear together long enough to record anything. Hopefully in the next few weeks, I'll be able to get something together.

Anybody see this? JCA doing full custom mods, including EL34s????

[video]http://youtu.be/J6_QV4Vjjt8[/video]

Yup. Already working out my order!

GRIMESPACE wrote:Anybody see this? JCA doing full custom mods, including EL34s????

[video]http://youtu.be/J6_QV4Vjjt8[/video]

Wow, man. Looks like sahlomonic will get a nice Christmas present this year!

I think Doug has been snooping this thread a bit!

Was just going through a few changes to my buddy's 22H. Used the Splawn Quickrod as an inspiration for the changes, and I must say, it woke this little amp RIGHT up. Still going through some of the peaker caps to get the treble just right, a few of the voltage dividers and mess with the fizz cap values. Added some much needed clarity and brightness and tightened the bottom end up nicely. I'll post more when I get it right. I'm really loving this amp.

Hey howdy, JCA22H owner here.

I'm *moderately* experienced inside an amp, have successfully built a kit amp (TriWatt, a fairly complex build). Anyways, I retubed my amp tonight....I am able to measure the B+ @ 373. I know where the bias trimmer is. But I can't for the life of me figure out where to measure the actual bias....I know to set my meter to mA. Help a brother out?

You're going to need a bias tester, which needs to go inline with the tube to measure current while the amp is running - unless you do a mod to install a bias test point. Best bet is to check with one of the better tube suppliers (I got mine at Eurotubes, and it was pretty cheap) - they'll generally help you determine what the optimal bias starting point should be.

Nice having you hear! I'm sure Jay or one of the other regulars will chime in soon.

keto wrote:Hey howdy, JCA22H owner here.

I'm *moderately* experienced inside an amp, have successfully built a kit amp (TriWatt, a fairly complex build). Anyways, I retubed my amp tonight....I am able to measure the B+ @ 373. I know where the bias trimmer is. But I can't for the life of me figure out where to measure the actual bias....I know to set my meter to mA. Help a brother out?

If you can't get a bias probe or don't wanna wait for one and you don't wanna mod the thing, you can use this method http://www.youtube.com/watch?v=V4T83PgEIhc

bare in mind you have 370 not 350 in b +

Best Regards

maynardo wrote:

keto wrote:Hey howdy, JCA22H owner here.

I'm *moderately* experienced inside an amp, have successfully built a kit amp (TriWatt, a fairly complex build). Anyways, I retubed my amp tonight....I am able to measure the B+ @ 373. I know where the bias trimmer is. But I can't for the life of me figure out where to measure the actual bias....I know to set my meter to mA. Help a brother out?

If you can't get a bias probe or don't wanna wait for one and you don't wanna mod the thing, you can use this method http://www.youtube.com/watch?v=V4T83PgEIhc

bare in mind you have 370 not 350 in b +

Best Regards

Yeah, I tried that from the vid, but couldn't get a reading, I think it's probably not knowing how to set my MM for current not volts.

Hi, my name is Chris. I've been creeping these boards for a while (and the HC mod thread that Edge11 started) and finally created an account.

My setup is the JCA22H stock into a Seismic Audio 2x12 cabinet, open back, with WGS Veteran 30 and ET65 speakers. I have two guitars, an Ibanez RG120 with Dimarzio Tone Zone in the bridge and a Kramer Baretta neck thru with EMGs and a Floyd Rose.

Currently tube rolling with a Tung Sol 12ax7 reissue, JJ ECC83s, and Groove Tubes GT7025 trying to find "that sound."

I'm glad to have found so many other enthusiasts.

sanch0 wrote:Hi, my name is Chris. I've been creeping these boards for a while (and the HC mod thread that Edge11 started) and finally created an account.

My setup is the JCA22H stock into a Seismic Audio 2x12 cabinet, open back, with WGS Veteran 30 and ET65 speakers. I have two guitars, an Ibanez RG120 with Dimarzio Tone Zone in the bridge and a Kramer Baretta neck thru with EMGs and a Floyd Rose.

Currently tube rolling with a Tung Sol 12ax7 reissue, JJ ECC83s, and Groove Tubes GT7025 trying to find "that sound."

I'm glad to have found so many other enthusiasts.

Welcome! Glad to have you on board. Would be very interested to hear what you think about the speaker pair you're running - especially if you have something to compare to, like the Celestion V30s I keep wanting to try out. Make sure you check out the prior pages here - lots of good stuff!

GRIMESPACE wrote:

sanch0 wrote:Hi, my name is Chris. I've been creeping these boards for a while (and the HC mod thread that Edge11 started) and finally created an account.

My setup is the JCA22H stock into a Seismic Audio 2x12 cabinet, open back, with WGS Veteran 30 and ET65 speakers. I have two guitars, an Ibanez RG120 with Dimarzio Tone Zone in the bridge and a Kramer Baretta neck thru with EMGs and a Floyd Rose.

Currently tube rolling with a Tung Sol 12ax7 reissue, JJ ECC83s, and Groove Tubes GT7025 trying to find "that sound."

I'm glad to have found so many other enthusiasts.

Welcome! Glad to have you on board. Would be very interested to hear what you think about the speaker pair you're running - especially if you have something to compare to, like the Celestion V30s I keep wanting to try out. Make sure you check out the prior pages here - lots of good stuff!

They've got a good rock sound. They were recommended by WGS as the best combination, even though the Retro 30 was recommended for the JCA20h, I didn't need a brighter speaker. I don't have anything to compare them to other than an EVM 12L from the 80s that I have in a combo. That one is very loud and doesn't break up well. It's mostly designed for clean headroom, I believe.

EDIT: Hey Steve, I noticed you have an EVM 12L as well. I wonder how yours compares to mine.

Of all the tubes I've rolled into and out of my JCA 2212RC, I've come back to Sovtek!!
It seems to me that every time I try some fancy tube brand in an EL-84 based amp
I go back to the Sovteks!! They just sound great. I'm coming around to the fact that they are a very good reliable tube
that are way to maligned on many forums. I do have jjs in the preamp positions but
the power tubes seemed to have the biggest effect on the tone of this amp.
I LOVE this amp and with an OCD in front and a Boss RV-5 in the loop (it works well with either channel and I really like the crunch channel with the gain at noon) it sounds amazing.
It's soo good that it's hard to stop playing through it.

sanch0 wrote:

GRIMESPACE wrote:

sanch0 wrote:Hi, my name is Chris. I've been creeping these boards for a while (and the HC mod thread that Edge11 started) and finally created an account.

My setup is the JCA22H stock into a Seismic Audio 2x12 cabinet, open back, with WGS Veteran 30 and ET65 speakers. I have two guitars, an Ibanez RG120 with Dimarzio Tone Zone in the bridge and a Kramer Baretta neck thru with EMGs and a Floyd Rose.

Currently tube rolling with a Tung Sol 12ax7 reissue, JJ ECC83s, and Groove Tubes GT7025 trying to find "that sound."

I'm glad to have found so many other enthusiasts.

Welcome! Glad to have you on board. Would be very interested to hear what you think about the speaker pair you're running - especially if you have something to compare to, like the Celestion V30s I keep wanting to try out. Make sure you check out the prior pages here - lots of good stuff!

They've got a good rock sound. They were recommended by WGS as the best combination, even though the Retro 30 was recommended for the JCA20h, I didn't need a brighter speaker. I don't have anything to compare them to other than an EVM 12L from the 80s that I have in a combo. That one is very loud and doesn't break up well. It's mostly designed for clean headroom, I believe.

EDIT: Hey Steve, I noticed you have an EVM 12L as well. I wonder how yours compares to mine.

I do have an EV speaker, but it's mounted into a Thiele TL806 box I built into a 2x12 paired with a Boogie (Celestion) MC-90 that's got approximately 1/4 of an open back. I haven't run my JCA50 with that combo much yet - it's mainly been run in conjunction with the old Line6 4x12 that's got a set of Celestion speakers in it that sounds pretty good to my ears. When I get my new studio completed (see my DIY thread referenced in my signature for info), I plan to do a lot of dialing of my sound at louder volumes than the bedroom stuff I've done to this point. Then we'll see just how much I like the speakers I have and will hopefully get to try out something with V30s at some point. The WGS stuff is real compelling to me, but I wish there was a way to try them out - shipping costs keep me from even thinking about buying without hearing them in person first...

jhall wrote:Of all the tubes I've rolled into and out of my JCA 2212RC, I've come back to Sovtek!!
It seems to me that every time I try some fancy tube brand in an EL-84 based amp
I go back to the Sovteks!! They just sound great. I'm coming around to the fact that they are a very good reliable tube
that are way to maligned on many forums. I do have jjs in the preamp positions but
the power tubes seemed to have the biggest effect on the tone of this amp.
I LOVE this amp and with an OCD in front and a Boss RV-5 in the loop (it works well with either channel and I really like the crunch channel with the gain at noon) it sounds amazing.
It's soo good that it's hard to stop playing through it.

I've been real happy with the full set of JJs I purchased shortly after buying my 50H. Those, plus setting the bias made a massive difference over the stock tube. Unfortunately, I haven't had an experience with other tubes (yet), other than trying out one of the old RCA 12AT7s from my '73 Fender Pro Reverb in V1 (which I didn't really like). I've heard great things about the Sovtek 6L6WXT+ for power on the 50/100, and will probably be the next set I go with for my 50H. I'm also really interested in lowering the OD gain, and may try a Jan Philips 5751 in V1 to try to tame things, and may also experiment with the phase inverter.

Good to hear about your success with the OCD - I have a Joyo Ultimate Overdrive (OCD clone) that I plan to try out when I get the studio up and running so I can give it all a workout.