Mesa STR 420 Tube Manufacturer?

[Simon Dorn]

Hi,
i bought an almost mint '93 Mesa Dual Rectifier Rev F (early one with serial #R07xx) which still has its original tubes in it.
It's still sounding great! I've read somewhere that the STR 420 is of chinese origin. They are all coke bottles. Is that correct? What about the preamp tubes of that era? Where do they come from? I think i will leave the tubes in the amp for some more time, 'cause i'm afraid that i will loose something, when i replace them
What do you think?
Regards, Simon

 

[BSRIAudio]

STR420s are Shuguang. I believe that's still Mesa's designation for 6L6s regardless of envelope shape.

Rectifiers don't really change dramatically with fancy power tubes in my experience. I have a quad of tubes that are the same as STR415s and my old rectifier didn't sound any better with them. They're biased cold enough that the output tubes are just doing a job and if they work then they work.

 

[FourT6and2]

Mesa STR-415 = Sylvania 6L6GC STR-387
Mesa STR-420 = Shuguang 6L6GC
Mesa STR-425 = Sovtek 5881/6L6WGC wafer-bottom
Mesa STR-430 = Sovtek 6L6WXT+ / Electro-Harmonix 6L6GC
Mesa STR-440 = Ruby 6L6GC MSTR
Mesa STR-447 = Electro-Harmonix EL34 (clone of the RFT EL34)
Mesa STR-450 = RFT/Siemens EL34

 

[Simon Dorn]

Cheers!
Are you sure that the Coke Bottle STR 420 were already Shuguangs', 25 years ago?
What about the preamp tubes?
Anyway my Rev F sounds great, with all the omph,grind and sizzle you can ask for
Regards,
Simon

 

[mnemonic]

Im not sure what to think about the STR420’s, my recto came with a mismatched set of tubes including two original STR420’s (non-coke bottle, though from the pictures I’ve seen the coke bottle 420’s appear to have the same internals).

I thought they were Chinese until someone told me they were Russian 6P3S.

https://tubes-store.com/product_info.php?products_id=23

They look the same as the STR420’s I pulled out of my recto, except for the Cyrillic writing.

 

[Rex Rocker]

They could be Chinese copies of those Russian 6P3S's.

https://www.ebay.com/itm/NEW-6L6GC-Pair ... SwhqhZ84PL

 

[psychodave]

I’ve got 2 brand new quads of those coke bottle 420’s.

 

[Simon Dorn]

From the early nineties?

 

[psychodave]

From the early nineties?

Yup.

 

[FourT6and2]

Mesa also labeled these as STR 420L, no? As far as I know they're all Shuguang. Even the old ones from back in the day. China has been around a long time folks.

 

[Simon Dorn]

From the early nineties?

Yup.

Cool. Where did you buy it?

 

[Simon Dorn]

Mesa also labeled these as STR 420L, no? As far as I know they're all Shuguang. Even the old ones from back in the day. China has been around a long time folks.

Yeah, since 3500 years
Shuguang since 1958. I just checked.

 

[psychodave]

From the early nineties?

Yup.

Cool. Where did you buy it?

I bought them many years ago.

 

[Racerxrated]

Mesa STR-415 = Sylvania 6L6GC STR-387
Mesa STR-420 = Shuguang 6L6GC
Mesa STR-425 = Sovtek 5881/6L6WGC wafer-bottom
Mesa STR-430 = Sovtek 6L6WXT+ / Electro-Harmonix 6L6GC
Mesa STR-440 = Ruby 6L6GC MSTR
Mesa STR-447 = Electro-Harmonix EL34 (clone of the RFT EL34)
Mesa STR-450 = RFT/Siemens EL34

I believe Mesa still has NOS 450s to this day, although not cheap I'm sure.

 

[BSRIAudio]

Mesa STR-415 = Sylvania 6L6GC STR-387
Mesa STR-420 = Shuguang 6L6GC
Mesa STR-425 = Sovtek 5881/6L6WGC wafer-bottom
Mesa STR-430 = Sovtek 6L6WXT+ / Electro-Harmonix 6L6GC
Mesa STR-440 = Ruby 6L6GC MSTR
Mesa STR-447 = Electro-Harmonix EL34 (clone of the RFT EL34)
Mesa STR-450 = RFT/Siemens EL34

I believe Mesa still has NOS 450s to this day, although not cheap I'm sure.

$180 a pair but all things considered I couldn't think of a more trustworthy source to spend that much cash on pairs of NOS EL34s.

https://store.mesaboogie.com/products/p ... -pair.html

 

[Exo-metal]

Mesa STR-415 = Sylvania 6L6GC STR-387
Mesa STR-420 = Shuguang 6L6GC
Mesa STR-425 = Sovtek 5881/6L6WGC wafer-bottom
Mesa STR-430 = Sovtek 6L6WXT+ / Electro-Harmonix 6L6GC
Mesa STR-440 = Ruby 6L6GC MSTR
Mesa STR-447 = Electro-Harmonix EL34 (clone of the RFT EL34)
Mesa STR-450 = RFT/Siemens EL34

Great reference except it's missing the STR-416

 

[FourT6and2]

Mesa STR-415 = Sylvania 6L6GC STR-387
Mesa STR-420 = Shuguang 6L6GC
Mesa STR-425 = Sovtek 5881/6L6WGC wafer-bottom
Mesa STR-430 = Sovtek 6L6WXT+ / Electro-Harmonix 6L6GC
Mesa STR-440 = Ruby 6L6GC MSTR
Mesa STR-447 = Electro-Harmonix EL34 (clone of the RFT EL34)
Mesa STR-450 = RFT/Siemens EL34

I believe Mesa still has NOS 450s to this day, although not cheap I'm sure.

$180 a pair but all things considered I couldn't think of a more trustworthy source to spend that much cash on pairs of NOS EL34s.

https://store.mesaboogie.com/products/p ... -pair.html

Correct. I did buy some a year ago. They arrived dead. Mesa sent me a new set. I trust Mesa over other third-party vendors.

 

[acalaf]

love your riffs Simon! I always make a face when listening to your yt videos.

 

[Simon Dorn]

Thanks!? What kind of face?

These are missing also, in the list: https://store.mesaboogie.com/products/p ... -pair.html

 

[Exo-metal]

I know there's a joke about this face thing lol