Putting 6L6 in a Bogner Ultra Uber EL34 amp?

[stratjacket]

There are several mega threads on the Bigger Ultra Uber and the various power tubes options. I’ve read them all but didn’t get a direct declaration from them. So I thought I’d ask directly.

I have an Ultra Uber with EL34’s. I would like to have 6L6’s instead.

Other amps I own (KSR for example) can take either, just have to adjust the bias, no problem.

Can I do this in the Ultra Uber with just a bias change?
Or what would I need to do in order to put 6L6’s in it?
Or am I just shit outta luck and the only way is to get the UU that comes with 6L6’s?

Thanks

 

[peterc52]

I don’t know. But I’ve read elsewhere that the EL34 version takes KT88 also

 

[stratjacket]

I don’t know. But I’ve read elsewhere that the EL34 version takes KT88 also

I’d try that if it’s a straight deal and bias adjustment too

 

[RedB4Black]

I’d try that if it’s a straight deal and bias adjustment too

You can put KT88s in it. It’s in the manual. I ran KT88s in mine for awhile.

 

[tonedog]

You need a different transformer for 6L6s. NOT INTERCHANGEABLE according to the manual.

 

[stratjacket]

You can put KT88s in it. It’s in the manual. I ran KT88s in mine for awhile.

You are correct sir…damn I haven’t been hit with an RTFM in years, ha

 

[stratjacket]

You need a different transformer for 6L6s. NOT INTERCHANGEABLE according to the manual.

Yep, thanks to Mr R4B I just read through…that stinks

 

[stratjacket]

Ok, fuck it, I just ordered a set of KT88’s…$299 for a quad set of Gold Lions. Let’s hope they’re reliable…

 

[John4021]

Ok, fuck it, I just ordered a set of KT88’s…$299 for a quad set of Gold Lions. Let’s hope they’re reliable…

Gold Lions are durable and tonefull
Talked to Bogner about it and he gave the Thumbs up to running KT88's ad EL 34's

 

[HellraiserJohnny]

There are several mega threads on the Bigger Ultra Uber and the various power tubes options. I’ve read them all but didn’t get a direct declaration from them. So I thought I’d ask directly.

I have an Ultra Uber with EL34’s. I would like to have 6L6’s instead.

Other amps I own (KSR for example) can take either, just have to adjust the bias, no problem.

Can I do this in the Ultra Uber with just a bias change?
Or what would I need to do in order to put 6L6’s in it?
Or am I just shit outta luck and the only way is to get the UU that comes with 6L6’s?

Thanks

Hoping you know WHY you want KT88s. My guy in Russia (Myasnikov) explained to me the difference between 6L6 AND EL34 power tubes when he built my custom 50/50 tube amp. The EL34 will break up sooner gving you more power tube break up earlier than the 6L6. I had him put the EL34s in because I just don't play loud like I did 20 years ago and I like the little bit of power tube break up I get. The 6L6's have to be pushed really hard before they start to break up. I've played loud enough in my years to appreciate power tube break up (not really distortion). My Syn 50/50 has 4 x 6L6's and I have to blow the paint off the walls to get a touch of power tube break up. It's just not practical (without an attenuator) and the Syn 50/50 amp can't be re-biased - KT88 are never going to give you power tube break up unless you push the amp to the wall. I can only assume that's what you are going for?

 

[stratjacket]

Hoping you know WHY you want KT88s. My guy in Russia (Myasnikov) explained to me the difference between 6L6 AND EL34 power tubes when he built my custom 50/50 tube amp. The EL34 will break up sooner gving you more power tube break up earlier than the 6L6. I had him put the EL34s in because I just don't play loud like I did 20 years ago and I like the little bit of power tube break up I get. The 6L6's have to be pushed really hard before they start to break up. I've played loud enough in my years to appreciate power tube break up (not really distortion). My Syn 50/50 has 4 x 6L6's and I have to blow the paint off the walls to get a touch of power tube break up. It's just not practical (without an attenuator) and the Syn 50/50 amp can't be re-biased - KT88 are never going to give you power tube break up unless you push the amp to the wall. I can only assume that's what you are going for?

That sounds about right for me. There are many variables, but over the years I seem to get along with 6L6’s better. I play through a Redseven EVO Reactive Load so I do have the amps cranked to around 10 o’clock, it’d blow my ear drums if playing that loud through a cabinet.

I’ve had amps with KT88’s before and loved them. I had a Shiva 20th with KT88’s and loved it for a long time, traded it, then got another one with EL34’s and didn’t like it nearly the same so sold it. I don’t think I’m an EL34 lover. But will report back once I get them swapped.

I have the Uber Synergy module I play through a KSR power amp with 6L6’s and enjoy it more than my Ultra Uber. The UU has way more sound variety in it so I’m hoping a change of the EL34’s will do the trick. It’s fun trying shit anyway

 

[HellraiserJohnny]

That sounds about right for me. There are many variables, but over the years I seem to get along with 6L6’s better. I play through a Redseven EVO Reactive Load so I do have the amps cranked to around 10 o’clock, it’d blow my ear drums if playing that loud through a cabinet.

I’ve had amps with KT88’s before and loved them. I had a Shiva 20th with KT88’s and loved it for a long time, traded it, then got another one with EL34’s and didn’t like it nearly the same so sold it. I don’t think I’m an EL34 lover. But will report back once I get them swapped.

I have the Uber Synergy module I play through a KSR power amp with 6L6’s and enjoy it more than my Ultra Uber. The UU has way more sound variety in it so I’m hoping a change of the EL34’s will do the trick. It’s fun trying shit anyway

Yeah, me too. I have stacks and boxes of both pre and power tubes. My guitarist partner in crime has a couple MESA heads and we play the tube swap game all the time. I'm really looking forward to using my attenuator and cranking the Syn 50/50 and cutting some tracks with it again sometime soon.

 

[mr70ss]

That sounds about right for me. There are many variables, but over the years I seem to get along with 6L6’s better. I play through a Redseven EVO Reactive Load so I do have the amps cranked to around 10 o’clock, it’d blow my ear drums if playing that loud through a cabinet.

I’ve had amps with KT88’s before and loved them. I had a Shiva 20th with KT88’s and loved it for a long time, traded it, then got another one with EL34’s and didn’t like it nearly the same so sold it. I don’t think I’m an EL34 lover. But will report back once I get them swapped.

I have the Uber Synergy module I play through a KSR power amp with 6L6’s and enjoy it more than my Ultra Uber. The UU has way more sound variety in it so I’m hoping a change of the EL34’s will do the trick. It’s fun trying shit anyway

any report on the kt88 swap? Just was wondering how you like them. thanks

 

[TheGreatGreen]

From what I've been told by techs, and from what I remember hearing from Reinhold in some youtube video I can't cite, you can put 6L6's in an amp built for EL34's, but you might have to do some very slight modding, like adding a resistor somewhere or something, and even then, the impedance will be a little bit mismatched, but not so much that the amp can't still run and be healthy.

Legal speak: not liable for any amps blowing up like a fireworks factory.

 

[harddriver]

From what I've been told by techs, and from what I remember hearing from Reinhold in some youtube video I can't cite, you can put 6L6's in an amp built for EL34's, but you might have to do some very slight modding, like adding a resistor somewhere or something, and even then, the impedance will be a little bit mismatched, but not so much that the amp can't still run and be healthy.

Legal speak: not liable for any amps blowing up like a fireworks factory.

You can generally run a 6L6 tube in any EL34 amp as long as you have enough bias range in the bias supply circuit to bias them properly even if the Output transformers are optimized for EL34 impedance wise, Marshall ran 6550's/KT-88's with no issues, but you could also run 6L6 is you wanted to.

YOU CANNOT run EL34's in an amp built strictly for 6L6's because they usually wire the power tube socket for 6L6 pinouts only.

Usually amps that ran 6L6 and EL34 interchangeably had an EL34/6l6 switch that had different valued resistors switched in our out for whatever tube was being used at the time.

Probably best to just run some KT-88's in the amp but the 6L6' s can be done.

 

[harddriver]

That sounds about right for me. There are many variables, but over the years I seem to get along with 6L6’s better. I play through a Redseven EVO Reactive Load so I do have the amps cranked to around 10 o’clock, it’d blow my ear drums if playing that loud through a cabinet.

I’ve had amps with KT88’s before and loved them. I had a Shiva 20th with KT88’s and loved it for a long time, traded it, then got another one with EL34’s and didn’t like it nearly the same so sold it. I don’t think I’m an EL34 lover. But will report back once I get them swapped.

I have the Uber Synergy module I play through a KSR power amp with 6L6’s and enjoy it more than my Ultra Uber. The UU has way more sound variety in it so I’m hoping a change of the EL34’s will do the trick. It’s fun trying shit anyway

You could get some 6L6's current draw wise that will operate within the bias range of the El34's in the Bogner. But if Reinhold is specifically not recommending it he may have a reason. It is true the output transformer spec'd for EL34's impedance is not optimum for 6L6's but the amp can run them safely unless of course something in his specific design prohibits it.

 

[Nigel]

There are several mega threads on the Bigger Ultra Uber and the various power tubes options. I’ve read them all but didn’t get a direct declaration from them. So I thought I’d ask directly.

I have an Ultra Uber with EL34’s. I would like to have 6L6’s instead.

Other amps I own (KSR for example) can take either, just have to adjust the bias, no problem.

Can I do this in the Ultra Uber with just a bias change?
Or what would I need to do in order to put 6L6’s in it?
Or am I just shit outta luck and the only way is to get the UU that comes with 6L6’s?

Thanks

You’ll likely have to change a bias resistor.

Better yet, get some JJ KT77’s for the bottom and top of 6L6’s and keep that complex EL34 mid without modification.

 

[harddriver]

You’ll likely have to change a bias resistor.

Better yet, get some JJ KT77’s for the bottom and top of 6L6’s and keep that complex EL34 mid without modification.

Excellent suggestion Nigel! I completely blanked on the KT-77. The KT-77 will work in place of the EL34's and give a very similar if not exact low end and similar frequency response that he would get with a 6L6.

I guess some KT77's do draw some more current than EL34's so maybe double check with Bogner to make sure they will swap in 100% with no issue but they should.

 

[Nigel]

Excellent suggestion Nigel! I completely blanked on the KT-77. The KT-77 will work in place of the EL34's and give a very similar if not exact low end and similar frequency response that he would get with a 6L6.

I guess some KT77's do draw some more current than EL34's so maybe double check with Bogner to make sure they will swap in 100% with no issue but they should.

Thanks.

It’s the heater current, but the additional draw is negligible for a Bogner spec PT.

The JJ KT77 is the finest modem EL34 type available. Cleans, grind, solos, nothing touches it, similarly to the JJ ECC803s, which the Uber Ultra uses in all slots.

 

[OldGtrGuy]

Do not put 6L6 in your 34 Ultra, they have different transformers designed for that tube type.

EL34 Ultra Can safely take KT88 and any EL34 variant, I'm actually trying KT77 in mine next week but do not put 6L6 in there.