Soldano SLO preamp tubes advice pls

[jaykay73]

Just scored a SLO with a 6L6 / EL34 switch in the rear. Currently loaded with Mullard EL34s.

The previous owner accidentally broke 2 of the preamp tubes. So I have three... Wondering which preamp tube slots they would best go and seeking suggestions about which other 2 I should buy.

I've emailed tech@soldano.com and still awaiting a reply.

The tubes I have are:

1. Sovtek 12ax7 LPS
2. Sovtek 12ax7 LP
3. JJ ECC83s

I've read conflicting reports about whether the LPS should or should not be used in the phase inverter position.

Please advise which tube should go where & what to buy to fill the 2 empty spots.

Thanks,

JK

 

[Racerxrated]

Just scored a SLO with a 6L6 / EL34 switch in the rear. Currently loaded with Mullard EL34s.

The previous owner accidentally broke 2 of the preamp tubes. So I have three... Wondering which preamp tube slots they would best go and seeking suggestions about which other 2 I should buy.

I've emailed tech@soldano.com and still awaiting a reply.

The tubes I have are:

1. Sovtek 12ax7 LPS
2. Sovtek 12ax7 LP
3. JJ ECC83s

I've read conflicting reports about whether the LPS should or should not be used in the phase inverter position.

Please advise which tube should go where & what to buy to fill the 2 empty spots.

Thanks,

JK

With the SLO its really a matter of trying different pre tubes in all the positions to see what you like best. I used a Jan 12at7 in my PI, but that Sovtek should work fine. I liked Chinese 8th/9th gen in all other slots. Wafer bottom Sovtek 5881s for power tubes. Experiment with the pre tubes! That's the only way...there's a ton of threads out there with suggestions.

 

[godgrinder]

I use JJ ECC83MG in V1/2/4 and Svetlana 12AX7 in V3 for my HR50+.
My SLO100 should be arriving next week, gonna try if the same combination works.

 

[steve_k]

Use the LPS in V5 (the PI).

Sovtek LP in V1

Regular JJ's in V2/V3/V4 or other short place tubes. Chinese work fine too.

As an alternative, I like the JJ ECC803 in V1. Knocks the gain back a tad.

 

[jaykay73]

Thanks for the tip.

I found another thread where Bill indicated the LPS tube is fine in V5 but definately should not be used in V2-4 because the spiral filaments running at constant max voltages will not hold up for long.

JK

 

[sg guy]

-try them all in every position-

-what ever sounds best to you,.. is whats best-

-I prefer NOS long plate -(anything)- in V1 at the very least,..

 

[barnesjd]

I wonder if the feedback on this thread will translate well to my SLO clone....

 

[FourT6and2]

Generally speaking, no long plate or spiral filament tubes in cathode follower positions unless you've elevated the heaters. So yeah, the LPS in PI position, LP in V1, and JJs in the others should be good. I think that's close to what I'm running right now. I might have an ECC803S in V2 and a Tung-Sol in V1. But JJ and Sovtek in the others. Not a huge difference regardless of what you use to be honest.

 

[SLOgriff]

Use the LPS in V5 (the PI).

Sovtek LP in V1

Regular JJ's in V2/V3/V4 or other short place tubes. Chinese work fine too.

As an alternative, I like the JJ ECC803 in V1. Knocks the gain back a tad.

Yeah, what he said.... The SLO is finicky amp though. Sometimes JJ's sound good in all positions with an LP or LPS in V5. 12AX7EH (Electro Harmonix) also sounds good in V2. You can really fine tune an SLO with just one tube change.

Not too sure about the EL34's. The DeYoung's can handle them but 5881/6L6's is where it shines.

 

[steve_k]

Thanks for the tip.

I found another thread where Bill indicated the LPS tube is fine in V5 but definately should not be used in V2-4 because the spiral filaments running at constant max voltages will not hold up for long.

JK

correct.

 

[Rick Lee]

I started out with JJs and then tried a mish mash of Chinese a Svetlana. When I had it in the shop for LDR noise, my tech put NOS GEs in there and it sounded amazing. They weren't cheap, but they were worth it.

 

[Mr. Willy]

I started out with JJs and then tried a mish mash of Chinese a Svetlana. When I had it in the shop for LDR noise, my tech put NOS GEs in there and it sounded amazing. They weren't cheap, but they were worth it.

That's what's in mine, V1 and V2. I can confirm the diagnosis above.