What does TWEED POWER technically do?

[willrock]

i tried the almighty search function but no luck. i know it starves the PT of some power to lower the amps headroom. but im looking for a more detailed description of how it works especially on mark IV coz i personally like the sound i get from it with my ebmm jp6, not as harsh and bright as in full power.. any gurus wants to chime in?

 

[Boogiebabies]

It knocks the primary voltage from 117V to around 90V like a variac. The secondary voltages go down as well.
It was done to "Brown" the amp out a bit. RCS claims he came up with the idea from watching EVH setting his variac at
a sound check.

 

[willrock]

thanks boogiebabies, i was hoping youd share something. so this explains the softer, feel with the IV if it is in tweed? it seems like the majority of us here likes it likes it on full power on the gigs, but imo tweed has more than enough power on most gigs. plus gets my tubes to last a little longer. anyone use the tweed at all aside from practicing at home?

 

[topcat0399]

thanks boogiebabies, i was hoping youd share something. so this explains the softer, feel with the IV if it is in tweed? it seems like the majority of us here likes it likes it on full power on the gigs, but imo tweed has more than enough power on most gigs. plus gets my tubes to last a little longer. anyone use the tweed at all aside from practicing at home?

For the small clubs that we regularly play; my mark iv is in tweed/class A most of the time. If I were to run some of the settings guys around here use I'd be deaf (er).


I LOVE THIS AMP!!!

cheers

tc

 

[willrock]

in fact i love the tweed power so much that i wanted it on my mark III. i called Mike B bout it but sadly, he said that mark IIIs output trannys doesnt have the option to do it... so he just suggested to use a real variac.

 

[Boogiebabies]

The MK IV PT # 561140 is a direct replacement for the MK III PT. If your PT blew, you would only be able to get a MK IV 561140 PT from Mesa.
The 562003 and 562004 OT's are identical other than the 562004R1. These should have no issues either with Tweed power.
You may have the 561136 PT which is the same as the 561140 and has the tweed function and a 5V rectifier heater as they were
used both used in MK IV's and Dual Rectifiers. The early 561136 in the Dual Rectifier is labeled Bold/Spongy and is the same as Tweed.
It's work a PT # check.

 

[willrock]

The MK IV PT # 561140 is a direct replacement for the MK III PT. If your PT blew, you would only be able to get a MK IV 561140 PT from Mesa.
The 562003 and 562004 OT's are identical other than the 562004R1. These should have no issues either with Tweed power.
You may have the 561136 PT which is the same as the 561140 and has the tweed function and a 5V rectifier heater as they were
used both used in MK IV's and Dual Rectifiers. The early 561136 in the Dual Rectifier is labeled Bold/Spongy and is the same as Tweed.
It's work a PT # check.

oh man, i hope i have those kinds.. by the way i have a red stripe, and its under maintenance at boogie right now.. what are the chances i have that kind of PT?

 

[Boogiebabies]

The MK IV PT # 561140 is a direct replacement for the MK III PT. If your PT blew, you would only be able to get a MK IV 561140 PT from Mesa.
The 562003 and 562004 OT's are identical other than the 562004R1. These should have no issues either with Tweed power.
You may have the 561136 PT which is the same as the 561140 and has the tweed function and a 5V rectifier heater as they were
used both used in MK IV's and Dual Rectifiers. The early 561136 in the Dual Rectifier is labeled Bold/Spongy and is the same as Tweed.
It's work a PT # check.

oh man, i hope i have those kinds.. by the way i have a red stripe, and its under maintenance at boogie right now.. what are the chances i have that kind of PT?

Not that good if it's a red stripe. Green would have been more likely.

 

[Podicle]

If tweed power is the same as using a variac, does this mean that I can lower the voltage on the export transformer on my 60w Mark III and get the same effect? In Australia we operate at 240v, which is the highest setting on the transformer. Can I try going lower to get a 'browner' sound or will this damage the amp? If I can go lower, how much so?
Cheers

 

[Boogiebabies]

If tweed power is the same as using a variac, does this mean that I can lower the voltage on the export transformer on my 60w Mark III and get the same effect? In Australia we operate at 240v, which is the highest setting on the transformer. Can I try going lower to get a 'browner' sound or will this damage the amp? If I can go lower, how much so?
Cheers

No, under the load from the power tubes it's only seeing 420-430V to the plates. That's brown enough at moderate volume and sags quite nicely.
Using any other setting can damage the amp since it's a step up/step down instead of a tweed/spongy type primary voltage dropper.

 

[Podicle]

Thanks again for your advice.

 

[scottywompas]

I go back and forth. I have used tweed power on gigs. I guess it just depends on my mood. I love both full power tone and tweed power tone.

Scott

 

[mule#1]

Does anybody notice a "looser" feel when using tweed in class A?

 

[willrock]

tweed is definitely looser, it can be good and bad though, so you better be careful. I've used tweed power live for couple of years now on gigs, it sounds really nice with my musicman petrucci on pentode/simulclass mode on a lot of venues. But i still prefer the sound of full powers' immediate attack and use it as much as i can whan the venue is right!

 

[mule#1]

I've been using mostly full power myself. I really like the looser feel of my 50+ though. I think I'll try the tweed again.

 

[igfraso]

If tweed power is the same as using a variac, does this mean that I can lower the voltage on the export transformer on my 60w Mark III and get the same effect? In Australia we operate at 240v, which is the highest setting on the transformer. Can I try going lower to get a 'browner' sound or will this damage the amp? If I can go lower, how much so?
Cheers

I am not sure what you are trying to say. I think it is just the opposite.

If you are living in Italy or Spain where the real voltage is 220V (nominal is 230V), you might set the voltage selector to 240V and the amplifier will sound different (browner?, lower volume?) because you are loading the amp with a lower voltage than the one it is expecting (according to the voltage selector).

If you are in Australia and set the export transformer to a lower voltage, you will be loading the amp with a higher voltage than the one the amp is expecting.

I apologize in advance if I am saying something wrong.

 

[cho]

in fact i love the tweed power so much that i wanted it on my mark III. i called Mike B bout it but sadly, he said that mark IIIs output trannys doesnt have the option to do it... so he just suggested to use a real variac.

I asked the same thing at MB Hollywood, and they gave me a similar answer. I wonder though.. The Simul Satellite had the Tweed option, and I thought it used the same components as the Mark III, but I could be wrong about that...does anybody know?

 

[Mongo1]

As best I can tell the Simul Sattelite is built directly off of the MKIII components. It's probably closest to a green stripe. I just finished recapping my SimulSat and it's such an early one (009), that its actually housed in a MKIII chassis.

 

[cho]

As best I can tell the Simul Sattelite is built directly off of the MKIII components. It's probably closest to a green stripe. I just finished recapping my SimulSat and it's such an early one (009), that its actually housed in a MKIII chassis.

That would imply that you could have the tweed option on a MIII, but I suppose it probably does depend on the transformers...

 

[Mongo1]

It would seem the MKIII's may not have had a tweed option.
I'm not that familiar with their options.

This thread seems to think the Simul-Sat's were based on a IVa.
I'll pull my IVa chassis one of these days and see, but the innards of my Simul-Sat look a lot like a MKIII to me...

http://forum.grailtone.com/viewtopic.php?f=3&t=27803&p=205695&hilit=+mark+III+tweed#p205695