57 Tweed Twin - upgrades?

Mastervolume

Member
Messages
2,094
I just purchased a 57 Tweed Twin and love the amp but wanted to see if I couldn't get another 20% of tone out of her.

I am changing all of the cheap Illinois coupling caps but also thought that a mercury OT and choke might also be in order.

Anybody change theirs?
 

hogy

Silver Supporting Member
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13,196
20%? You can get another 100% out of it by ditching the stock speakers and installing a pair of Celestion Blues.
 

gregc

Silver Supporting Member
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3,924
Pretty sure it's not a 2 ohm load. I know there was misprint in some of the documentation.
 

Mastervolume

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2,094
When I picked the amp up the Bias was set @ 19ma. It maxed out @ 23ma. 70% is something like 38ma. I needed to change a resistor to get the tubes to bias into spec. There is no way that this amp could have left the factory biased correctly.

These are GT "blackplate" 6l6s with a rating of 5 which should fall into the middle of the spectrum.

I have read reviews of the amp where people have played one and hated it and then had a chance to play another one and loved it.... my guess is that this cold bias is the norm on these amps.
 

myles111

Member
Messages
2,954
When I picked the amp up the Bias was set @ 19ma. It maxed out @ 23ma. 70% is something like 38ma. I needed to change a resistor to get the tubes to bias into spec. There is no way that this amp could have left the factory biased correctly.

These are GT "blackplate" 6l6s with a rating of 5 which should fall into the middle of the spectrum.

I have read reviews of the amp where people have played one and hated it and then had a chance to play another one and loved it.... my guess is that this cold bias is the norm on these amps.
Improper bias on Fender amps from the factory is quite common. Fender breaks down the 10 point GT scale into 3 ranges, red, white, blue.

Red = GT 8-10
White = GT 4-7
Blue = GT 1-3

A #5 is still a cooler rating and if you go to a #7 you will see your plate dissapation rise without changing the bias at all. You will then be in range where your bias pots swing would be more inline with the tube.

As a side note I prefer #7's in these amps biased at 60%ID based on the amps plate voltage.

If you think these things are biased cold from the factory measure most Mesa amps! Their six color codes covert to the GT scale in this way:

red yellow - #4
green gray - #5
blue white - #6

Since Mesa amps have a fixed bias (on their class A/B amps) their own tubes are supplied in these tighter ranges. I find the red and yellow range reads down below 30% ID many times. If your amp has those then replacing them will yield improvement.

Green / Gray are still cold.

Blue / White gets you in the ballpark but many times Mesa does not have those in stock.
 

jay42

Member
Messages
7,024
If you want to sound like EC, make sure they didn't load it with all 12ax7s. V1, V2, and V3 should be 12ay7s.

What's the deal with the stock speakers? I thought those Emi/Webers were supposed to be very nice.
 

Mastervolume

Member
Messages
2,094
OK so I ordered up the sozo's

Put in a couple orange drops to tide me over.

The amp ships stock with mercury trannies....no wonder it sounds as good as it does.

Replaced the speakers with blues this morning....

WOW

Hogy you were right. I have the chime and clarity of an AC30 with more tone shaping and it is quieter and bigger sounding.

I think I am in love.
 

hogy

Silver Supporting Member
Messages
13,196
Replaced the speakers with blues this morning....

WOW

Hogy you were right. I have the chime and clarity of an AC30 with more tone shaping and it is quieter and bigger sounding.

I think I am in love.
:)

It's a magical combination.
 

jakins

Member
Messages
389
can you crank that amp with blues in it? i guess theyre rated around 35 watts, right? you aint in love with no amp, sheeiiit. ill be waiting patiently to pounce on it when you get sick of it.
 

myles111

Member
Messages
2,954
can you crank that amp with blues in it? i guess theyre rated around 35 watts, right? you aint in love with no amp, sheeiiit. ill be waiting patiently to pounce on it when you get sick of it.
Vox blues are 15 watters and even an AC-30 was pushing them.

You should go to the golds.
 

pedalcr8z

Member
Messages
3,436
I just purchased a 57 Tweed Twin and love the amp but wanted to see if I couldn't get another 20% of tone out of her.

I am changing all of the cheap Illinois coupling caps but also thought that a mercury OT and choke might also be in order.

Anybody change theirs?

It ALREADY comes with a Mercury Magnetics OT's! Don't confuse "brighter" (which the Celestion Blues indeed are) with "better".......the stock Weber designed and built blues are much creamier and smoother to my ears IMHO but if it's the sound of an AC-30 you're after, you sure went in that direction.....shame that you'll lose some Tweed magic but to each his own.....my fear is that you will overpower them. FWIW, there are many tube sellers stating that the stock GT-6L6GE's are the best sounding in the industry.....GT is actually manufacturing them in the old GE plant here in the states that they bought. There are some MAJOR artists using the amp as is......Clapton and Gilmour for starters.
 

jakins

Member
Messages
389
It ALREADY comes with a Mercury Magnetics OT's! Don't confuse "brighter" (which the Celestion Blues indeed are) with "better".......the stock Weber designed and built blues are much creamier and smoother to my ears IMHO but if it's the sound of an AC-30 you're after, you sure went in that direction.....shame that you'll lose some Tweed magic but to each his own.....my fear is that you will overpower them. There are some MAJOR artists using the amp as is......Clapton and Gilmour for starters.
if someone tweaks an amp to sound "better" to them...it is then, well, better.
 

Mastervolume

Member
Messages
2,094
It ALREADY comes with a Mercury Magnetics OT's! Don't confuse "brighter" (which the Celestion Blues indeed are) with "better".......the stock Weber designed and built blues are much creamier and smoother to my ears IMHO but if it's the sound of an AC-30 you're after, you sure went in that direction.....shame that you'll lose some Tweed magic but to each his own.....my fear is that you will overpower them. There are some MAJOR artists using the amp as is......Clapton and Gilmour for starters.
The amp was great as is.

claptons was made by John Suhr and doesn't share much in the way of components as the stock model.

Isn't clapton using tone tubbys?

The cheap coupling caps they use are horrible. Changing the coupling caps only enhances the tone that is already trying to come out of the amp.

Blues ride that line but the way I am going to use the amp 99.999999% of the time is as a cleanish platform with a pedalboard.

If I blow the blues then I think I'll tubby this badboy up. I think that the tubbys shine in tweeds.
 

hogy

Silver Supporting Member
Messages
13,196
can you crank that amp with blues in it? i guess theyre rated around 35 watts, right?
IMO, all day long. But you're on your own, you can blow them, especially with a fuzz face.

FWIW, I have had a pair of old, fragile, original Vox speakers in my '56 low power Twin for years, and they're holding up fine. In fact, I had a pair of RI Vox Blues in my '59 HIGH power Twin for 3 years with no ill effects. Original Marshall Bluesbreaker combos had the same speakers, too.
 




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