50/50 which tubes for which channel

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synner88tc
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50/50 which tubes for which channel

Post by synner88tc » Fri Dec 05, 2008 12:00 am

hey guy's

i have a mesa 50/50, i think it is the newer version (?) it has a blue power light. i am trying to figure out which of the 4 tubes represent which channels (A and B)

i picked up a pair of yellow jackets adaptors and i want to audition the tone in one channel and a/b it against stock.

so i went through a bunch of old threads and found both answers: left/right, and inside/outside. i dont want to mess up my amp by running a 6l6 and a el84 together on 1 channel, so i am hoping someone has a confident answer for me

cam
ada mp-1 (mod 4 mk 2)
ada mp-1 (SS)
mesa studio pre
hush IIcx
rocktron replifex
mesa 50/50
mesa half back 4x12
marshall 1960 4x12
ibanez SZ2020ex prestige, SZ320, SZ2550 prestige, RG270, RS430

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crane
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Re: 50/50 which tubes for which channel

Post by crane » Fri Dec 05, 2008 3:13 am

The old version, with 3 swirches on the left (power, stdby and hi/lo power) has the tubes separated left/right for the two channels.

Image

I dont know for the new version (red light ? only power and stdby switches)

Image
PRS McCarty Soapbar with BKP Pigs90, PRS custom 22 with BKP Rebel Yell
Mark V Head, 1x12" Mesa 1/2 closed (EVM-12L)
Triaxis 2.0 noFat - Quad preamp
Deep modded 20:20 - Bias modded 50/50 - SimulClass 295
Home made amps/speakers/pedals

synner88tc
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Re: 50/50 which tubes for which channel

Post by synner88tc » Fri Dec 05, 2008 12:53 pm

thanks!

i guess i was confused, i though there was 2 versions of the old 50/50 which is what i have.

mine is exactly like in the first pic.

i will post some results when i try it out tonight.

cam
ada mp-1 (mod 4 mk 2)
ada mp-1 (SS)
mesa studio pre
hush IIcx
rocktron replifex
mesa 50/50
mesa half back 4x12
marshall 1960 4x12
ibanez SZ2020ex prestige, SZ320, SZ2550 prestige, RG270, RS430

joe web
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Re: 50/50 which tubes for which channel

Post by joe web » Fri Dec 05, 2008 3:02 pm

The tubes are located this way :

back
I B B A A I---------------
I
I
I
I
I_________a_a__b_b___I
front

A, B: Tubes
a, b : channel controls
Joe´s Band: Risky Whisky; Morbid Sky

synner88tc
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Re: 50/50 which tubes for which channel

Post by synner88tc » Fri Dec 05, 2008 8:28 pm

well i can confirm that is indeed the order, many thanks!

i only had a few min to play so i will come back with results later.

cam
ada mp-1 (mod 4 mk 2)
ada mp-1 (SS)
mesa studio pre
hush IIcx
rocktron replifex
mesa 50/50
mesa half back 4x12
marshall 1960 4x12
ibanez SZ2020ex prestige, SZ320, SZ2550 prestige, RG270, RS430

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vipmetal
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Re: 50/50 which tubes for which channel

Post by vipmetal » Tue Dec 21, 2010 3:20 am

Are the tube positions same with new stereo2:Fifty power amp??
— MESA AMPS —
Mesa Roadking (2002)&Mesa TriAxis (2015), Recto 4x12
Single Recto (2010), 2x12 Vertical
- past -
Triaxis 2.0 Recto-board
Recto Pre
2:50
Mark V

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crane
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Re: 50/50 which tubes for which channel

Post by crane » Tue Dec 21, 2010 4:03 am

Never had a 2:50 in my hands, so I don't know.
PRS McCarty Soapbar with BKP Pigs90, PRS custom 22 with BKP Rebel Yell
Mark V Head, 1x12" Mesa 1/2 closed (EVM-12L)
Triaxis 2.0 noFat - Quad preamp
Deep modded 20:20 - Bias modded 50/50 - SimulClass 295
Home made amps/speakers/pedals

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vipmetal
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Re: 50/50 which tubes for which channel

Post by vipmetal » Tue Dec 21, 2010 5:37 am

Is there any way to check it out?
— MESA AMPS —
Mesa Roadking (2002)&Mesa TriAxis (2015), Recto 4x12
Single Recto (2010), 2x12 Vertical
- past -
Triaxis 2.0 Recto-board
Recto Pre
2:50
Mark V

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crane
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Re: 50/50 which tubes for which channel

Post by crane » Tue Dec 21, 2010 6:55 am

Yep.
Plug BOTH speakers and remove the 2 left tubes (or right). Turn the amp on and see if sound is coming from both spakers or not. If only one speaker.. well.. speaks then it's the same arrangement as the old 50/50. If sound comes out from both but distorted and weak, then it's an ABBA arrangement.
PRS McCarty Soapbar with BKP Pigs90, PRS custom 22 with BKP Rebel Yell
Mark V Head, 1x12" Mesa 1/2 closed (EVM-12L)
Triaxis 2.0 noFat - Quad preamp
Deep modded 20:20 - Bias modded 50/50 - SimulClass 295
Home made amps/speakers/pedals

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