Lazy J 20 valve change advice

russpm

I’m looking to tame my Lazy J 20 a wee bit by changing the 6L6 valves to 6v6 and a rectifier change.
Im looking for advice on the best suited valves to put in, someone suggested TAD.

Thoughts would be well received.

ecc83

I have no idea of the biasing arrangements of the LJ20 but it will need adjusting.  Up for that?

No doubt ICBM or another top boff' will be along shortly?

Dave.

russpm

Thanks. My understanding is it can be done without any biasing adjustment but I’m usually wrong 

4114Effects

ecc83 said:

I have no idea of the biasing arrangements of the LJ20 but it will need adjusting.  Up for that?

No doubt ICBM or another top boff' will be along shortly?

Dave.

It's cathode bias and designed so you can just change to a 5y3 rectifier and pop 6v6 in, as far as I can tell. OT primary is probably halfway between 6v6 and 6l6 values to accommodate this. 

4114Effects

But if it is set up this way, I'd go for some rugged modern 6v6gt that can take more voltage, JJ have a good rep for this. 

russpm

4114Effects said:

But if it is set up this way, I'd go for some rugged modern 6v6gt that can take more voltage, JJ have a good rep for this. 

4114Effects said:

ecc83 said:

I have no idea of the biasing arrangements of the LJ20 but it will need adjusting.  Up for that?

No doubt ICBM or another top boff' will be along shortly?

Dave.

It's cathode bias and designed so you can just change to a 5y3 rectifier and pop 6v6 in, as far as I can tell. OT primary is probably halfway between 6v6 and 6l6 values to accommodate this. 

Yes that’s my understanding too. Thanks man

breezytele

I did this swap a few years back (sticking with EHX valves)
I preferred the 6L6 set up and swapped back fairly soon after.

I think a ‘J20 with 6V6 valves is not the same as a J10’, the latter being clearly designed around the 6V6.

Still, you’ll no doubt enjoy the experiment. Jesse always recommends EHX

russpm

breezytele said:

I did this swap a few years back (sticking with EHX valves)
I preferred the 6L6 set up and swapped back fairly soon after.

I think a ‘J20 with 6V6 valves is not the same as a J10’, the latter being clearly designed around the 6V6.

Still, you’ll no doubt enjoy the experiment. Jesse always recommends EHX

Thanks man. Is it an easy enough swap? Not sure which valves are which as I can’t find a diagram.

4114Effects

russpm said:

breezytele said:

I did this swap a few years back (sticking with EHX valves)
I preferred the 6L6 set up and swapped back fairly soon after.

I think a ‘J20 with 6V6 valves is not the same as a J10’, the latter being clearly designed around the 6V6.

Still, you’ll no doubt enjoy the experiment. Jesse always recommends EHX

Thanks man. Is it an easy enough swap? Not sure which valves are which as I can’t find a diagram.

The 5ar4 rectifier will be the one that says 5ar4 on it. The 6L6 valves will be the ones that say 6L6 on them.

Seriously though, as you look at the back the first one on the left is the rectifier, next two are the 6L6. 

russpm

4114Effects said:

russpm said:

breezytele said:

I did this swap a few years back (sticking with EHX valves)
I preferred the 6L6 set up and swapped back fairly soon after.

I think a ‘J20 with 6V6 valves is not the same as a J10’, the latter being clearly designed around the 6V6.

Still, you’ll no doubt enjoy the experiment. Jesse always recommends EHX

Thanks man. Is it an easy enough swap? Not sure which valves are which as I can’t find a diagram.

The 5ar4 rectifier will be the one that says 5ar4 on it. The 6L6 valves will be the ones that say 6L6 on them.

Seriously though, as you look at the back the first one on the left is the rectifier, next two are the 6L6. 

Soz for being a pork chop!! Haha, thanks  that’s brilliant.

ecc83

I might point out that the ORIGINAL 6V6 was practically indescructable. I used to service radios fitted with the "Red octal series". Most faults were caps or crappy carbon comp' resistors gone high/oc or, very rarely a GZ32 or frequency changer. NEVER did I replace the 6v6. Some sets used an EL33 and they did fail sometimes.

Are modern 6V6s as bombproof as the old ones?

Dave.

Modulus_Amps

4114Effects said:

ecc83 said:

I have no idea of the biasing arrangements of the LJ20 but it will need adjusting.  Up for that?

No doubt ICBM or another top boff' will be along shortly?

Dave.

It's cathode bias and designed so you can just change to a 5y3 rectifier and pop 6v6 in, as far as I can tell. OT primary is probably halfway between 6v6 and 6l6 values to accommodate this. 

From discusions I have had the OT is actually better suited to 6V6's, same with the PT's

crunchman

I've tried it with the 5Y3 and 6V6s.  I didn't think it sounded as good.  When Jesse started offering power scaling as an option I got Jesse to add it to mine.  To my ears, that's a much better way to tame it than 5Y3 and 6L6s.

Wazmeister

Russ, does the power scaling not work for you ?

russpm

Wazmeister said:

Russ, does the power scaling not work for you ?

@Wazmeister - In the small practice space I have, it means  I have to roll the VAC all the way back. At this point the 20 doesn’t sound as good and also the tremolo is only just about useable. I’ve been using a Fryette PS2 and that is much better that the VAC. Impressive kit indeed. 

However I would like to push the amp a little more to get those lovely break up sounds in the sweet spot at lower volume, so was wondering if taming it with the valve change would bring down the overall volume without losing too much from the dynamics.
I’m going to give it a go and will no doubt change it back as it won’t sound as good 

cbellanga

When I was in the UK and had a band, I was always trying to control stage volume as some in my band had tinitus.

First thing was using the 6v6s - that helped a bit but it was still pretty loud for venues like pizzaexpress jazz club so I'd use the VAC all the way as well.

But the vac in my opinion also changes the amp ability to overdrive quite a lot.

Now that I'm pretty much just recording some guitar parts, I've bought a captor X and been doing some tests.

In my case I need the channel volume and the vac at least half way up to get that nice natural crunch out of the amp. Im not technical but only assume thats coming from the 6v6s and the vac srtarve the valves so they don't get into overdrive at higher settings.

So at the moment I'm using the captor X at -20db, vac half away and the channel volume at about 6-7.

Now I can also use the tone control a bit better and get that clean-up with the volume. Haven't tried with the 6l6s just yet but something to check.

If I'd go back to gigging I'd probably take the xcaptor with me and try to balance one of its attenuator settings with the vac for live volume.