Germino Classic 45

[riffmeister]

Any1 try regular 6L6's in this amp yet? Will this thin out the bass response a bit? I find the amp to be a bit bass-heavy for my taste (2x12 combo with greenbacks).

I'm going to have a go with the Groove Tube GE reissues this week.

[jkr]

I tried EL34s and that seemed to give more highs and less bass. I went back to KT66s because I liked there crunch, but EL34s seemed to do what you are asking. Just make sure you re-bias of course.

[riffmeister]

Thanks......so everything is simpatico with EL34's in this amp, too?

I just remember reading that Fender 6L6 amps can fry if EL34's are installed, something about the heater current draw being different between the two tube types.

[thelionsden]

I was talking to Jesse at Rockytop about the DC plexi which hdiddy had put el34 in and he said (from my memory so I could be in error but I doubt it) that the KT 66 were about twice the impedance of the el34 so if you use the el34 in an amp that was set up for kt66 you have to use a different speaker tap. i think it was that the 16 ohm tap would now be an 8 ohm tap and down the line. If you put a 16 ohm speaker into the 16 ohm tap (which is now really 8 ohms) I think it can be hard on the amp. I think I remember my tech telling me that having a higher ohm speaker into a lower rated tap can be harmful to an amp. I had always thought the opposite, that a higher ohm speaker wouild be a greater load and have less chance of harming it, but according to what I remember hearing, I think this is not true. Certainly there are people here that can confirm or debunk this if it is wrong....

[jkr]

Greg Germino himself tells you on the site to try the amp with EL34s. Him I spoke about it. Apparently it's no problem with the Classic 45.

[thelionsden]

Originally posted by jkr
Greg Germino himself tells you on the site to try the amp with EL34s. Him I spoke about it. Apparently it's no problem with the Classic 45.

In case you are referring to my post, I didn't say that you cant't use EL34...you can..You just may have to use a different speaker tap to have it right. And if you use the wrong speaker tap it may not be good.

[riffmeister]

Originally posted by jkr
Greg Germino himself tells you on the site to try the amp with EL34s. Him I spoke about it. Apparently it's no problem with the Classic 45.

Yes, I corresponded with Greg today by email, and he said "no problem" with 6L6's & EL34's. KT66's are a better match for the OT, though.

[tonedaddy]

Originally posted by thelionsden
I was talking to Jesse at Rockytop about the DC plexi which hdiddy had put el34 in and he said (from my memory so I could be in error but I doubt it) that the KT 66 were about twice the impedance of the el34 so if you use the el34 in an amp that was set up for kt66 you have to use a different speaker tap. i think it was that the 16 ohm tap would now be an 8 ohm tap and down the line. If you put a 16 ohm speaker into the 16 ohm tap (which is now really 8 ohms) I think it can be hard on the amp. I think I remember my tech telling me that having a higher ohm speaker into a lower rated tap can be harmful to an amp. I had always thought the opposite, that a higher ohm speaker wouild be a greater load and have less chance of harming it, but according to what I remember hearing, I think this is not true. Certainly there are people here that can confirm or debunk this if it is wrong....

I own a DC 45/50 and haven't heard this before.

To confirm this information, I've contacted Denis Cornell directly to confirm or clarify this on the 45/50. If he doesn't post a message directly, I'll post any reply I receive.

[thelionsden]

Originally posted by tonedaddy
I own a DC 45/50 and haven't heard this before.

To confirm this information, I've contacted Denis Cornell directly to confirm or clarify this on the 45/50. If he doesn't post a message directly, I'll post any reply I receive.

Thats cool I would be interested in hearing what he has to say. I am not trying to pass some bad info. I had hdiddy's dc45/50 over here to try as I was perhaps interested in buying it. He originally had GEC KT66 in it but had sold them and popped some EL 34 in and had it biased. I think they were Svets in there as I recall. The amp sounded real good for crunch but it had no clean headroom at all. It wasn't clean with the volume on 1. After giving it back to him he sold it the next day. After hearing about the KT66 having more clean headroom and that I may not have been using the right speaker tap, I didn't feel like the amp was given a fair shake and I would have liked to try it with the KT66, but when I called him back, he had sold it already. I can check this impedance issue with my own tech here he knows all that stuff too, I just haven't had a chance to run it by him yet.

Dennis

[tonedaddy]

Here's the answer from Denis about what's required when changing from KT66s to EL34s in the DC Plexi 45/50:

"All you need to do is to change the bias setting from 48 to -42 volts I have a sheet to show you how to do it but I can only FAX or post it to you.
Denis"


I requested a fax of the document, just to make sure there's nothing else on it, and I'll hopefully have it shortly and add it to this thread.


To Denis Cornell's credit, I sent my email to him at 1:41am this morning, and his reply was in my inbox less than 2 hours later.

Not bad considering he's on the other side of the Atlantic. This has been typical of Denis' communication with me, and just another example of Cornell's top notch customer service!

[riffmeister]

Originally posted by riffmeister
Yes, I corresponded with Greg today by email, and he said "no problem" with 6L6's & EL34's. KT66's are a better match for the OT, though.

I replaced the KT66's with NOS Siemens EL34's, and replaced the Chinese V1 with an RFT and the GT Mullard reissue PI with a Sovtek LPS.

The amp sounded WONDERFUL with the band tonight. Sat PERFECTLY in the mix and with, uh, well, CLASSIC sounding tones!

I'm a VERY happy camper with this amp now!

[hasserl]

The issue with the impeadance difference between the KT66's and EL34's is more of an issue with tone, not with damage to the amp. In an amp with an OT impeadance optimized for KT66's you MAY prefer the tone if you half the impeadance of the load with EL34's installed. If the amp has an impeadance selector switch you can move the selector to the next hgher position. i.e. with a 4 ohm speaker load put the selector switch at 8 ohms. This will reflect a load closer to what the KT66's like to see.

On the other hand you MAY NOT prefer the tone. If not, don't sweat it. Unless the amp is built with marginal components anyway it should be able to easily handle the mismatch. And it appears that Greg has already said it is alright to do on the Germino, so don't worry about it.

With the Fender amps the main thing to worry about is that pin #1 is tied to pin #8 or ground. Since 6L6's have pins #1 & #8 tioed internally they do not need an external connection, so Fender took advantage of this on some amps and used that pin as an anchor for something else. You can't just stick EL34's in an amp like this, it has to be set up for the EL34's. Also, EL34's do draw a bit more current for the heater filaments, so they may tax the power transformer. Just something to be aware of. But again, it looks like Greg has built his amps so they can safely run either 6L6's or EL34's or KT66's. Life is good!

[riffmeister]

Originally posted by hasserl
.....Greg has built his amps so they can safely run either 6L6's or EL34's or KT66's. Life is good!

I much prefer the sound of the Classic 45 with EL34's, as I discovered last night at band rehearsal. With a humbucker guitar and a couple of pedals, the tones were, uh........well........simply "Classic"!

I was running the amp through the bright channel. With the volume at about 1 oclock, I was able to use my guitar's volume control and get a great mix with the band for both rhythm and lead tones. I was using a Fulldrive as the dirt pedal and it sounded simply glorius with this amp.

Even with the EL34's, I find the amp to be somewhat bass-heavy, but I was able to get a great sound with the bass control "off" and adjusting the treb/mid/presence controls to taste.

This amp is amazingly sweet, I like it a lot!!

[TaronKeim]

That seems like an un-natural amount of lowend for the Classic 45, especially with Greenbacks... have you tried running it through a closed back cabinet? Perhaps it is just massively boomy due to the open back cab (very deep and resonant) and with Greenbacks having such a loose bass response already. It just seems strange to me that you have to play it with the control almost off, especially with how useful and toneful the Germino tone-stacks tend to be. On the other hand, glad you like it with the EL34's

-TJK

[tonedaddy]

Here's the faxed info from Denis Cornell regarding changing tubes in the DC 45/50:

"Bias voltage on high power: 42 volts negative for EL34 and 48 volts negative for KT66 output valves.

Bias Voltage on low power: 23 volts negative for EL34 and 28 volts negative for KT66 output valves."



This indicates that Denis Cornell is saying NO change in speaker impedance tap choice is required for using EL34 or KT66 tubes in the DC 45/50 (rather, just an adjustment in the bias voltage).

Hope that clears things up, and let me know if you have any more questions, as I'll get them clarified through Denis.