The Elmwood M90 - Tubes - Plate Voltage - Bias Settings

[Seitz333]

Thought I would create this thread and let everbody post their settings so we could compare.

With my Elmwood M90 I'm currently getting the following readings with the Factory tubes with my Weber Bias Rite:

Updated after fixing a socket pin and then did a re-bias.

Plate Voltage - 612v
Bias - 40mA & 39mA

According to the Weber Bias Calculator, the bias setting should be 40 mA

I'm thinking about changing to the Gold Lion KT88's and Tung-Sol pre-amp tubes, anybody tried these in the M90?

What is everybody else running?

Chuck

 

[Capulin Overdrive]

you must have some pretty high voltage at your wall outlets?


think my plate voltage runs around 590?


i use a Weber Bias Rite and thier calculator, and bias just a little under 70%, maybe around 68%.


it's pretty hard to beat the tubes Jan is shipping them with.


i've tried several deferent KT-88's and messed with deferent preamp tubes some.


i run a Tung-sol in V1 and the stock tubes in the rest of the preamp, and back to Elmwood labeled KT-88's for power. i like Jan's power tubes, as i feel they have a nice Marshally crunch to them.

Sovtek KT-88's sound was kindda good, but damned they felt nice to play on, and i mean way nice! however they kind of scared me that they could fail, the crome stuff on the inside of the tube sure blued/grayed up fast?


tried some Penta KTT88-98 and they were kindda bassy and not really the sound i was after. might be good for somebody?


tried some SED KT-88's, and didn't like them, but don't really remember why? i'm a total SED freak for allmost any amp that takes 34's or 6L6's, so who knows? allmost seems like the set i had couldn't handle the high plate voltage, because they sounded great in a VHT D60?


i haven't tried the Gold Lion KT-88's, but have tried the KT-77's and the KT-66's. i really like both of them, they both kindda have a similar modern mean sound to them!


so, ah, yea!

 

[steve_k]

Still running stock tubes across the board in mine as I haven't had time to mess with it much, but can't complain at all. Like the last poster, the SED's are all I buy for EL34 service and run them in the VH4 and Uberschall. Haven't had one fail yet. Tung Sol in V1 as takes care of most microphonic issues including most incoming text messages on the mobile phone! As this is my first KT88 amp, I will have to get a feel for what is out there, but haven't found a reason to change yet.

One thing though, with the high plate voltages, you start getting really limited on tubes to handle the output and maintain tube life. I would worry a little about running 34's or 6L6's in the thing as they would probably fry rather quickly. Think I will stay with the KT88's and let the little internal fan do its job.

I am 100% satisfied with the M90. As I said in Berts post in the other index, this amp has effectively sent my Uberschall to the closet and earned a spot in the road case, along with the VH4.

Steve

 

[Hacksaw]

Another SED freak here, too! I also prefer the tubes that came stock in the elmwood. Sorry to stick a non M90 amp in the thread.. I am running the M60, 465 v plate, and biased around 32, 60% I might heat it up hotter on the bias for fun today to 70% and see how much fun I have.

Still run the Tad preamp tubes. I did changed out the PI to a tad as well in m60 #2, added more life to the amp.

 

[rjmmusic]

Gold Lion KT88s and a mix of Tung-Sol and the stock 12AX7s for me. (Sorry, don't have the amp here and don't remember which positions I ended up putting the Tung-Sols in).

I like the Gold Lions because they don't have the treble harshness that the stock tubes sometimes had. They still crunch like a mofo, but are warmer and better balanced. Same for the Tung-Sols - warmed the amp of a bit. I kept at least one of the original 12AX7s in there, I believe in V2 to keep CH2 a little more aggressive sounding.

 

[arkame]

What is the kt88 elmwood?Shuguang or oder?

 

[61reissue]

Shuguang

 

[arkame]

Ok thank you.