IIc transformer ID

[sbalderrama]

I have a IIc in the + serial number range but someone mentioned once the transformer seemed to be not original. Can you please help ID the transformer in photo attached? Thanks.

 

[user 41014]

561136 is the PT found in Mark III, early Mark IV, early recto's, DC, etc
The date code looks like 2nd half of 1992

 

[Nick Athanasatos]

Are original transformers available to be bought for these IIC ?

 

[user 41014]

No, but if you've been following Jay's IIC+ build here he had some tranny's recently made.

Mercury Magnetics (or others) likely has one that will work but there is the 60, 100, 105, 180/190 so it depends on what you need.

 

[Nick Athanasatos]

No, but if you've been following Jay's IIC+ build here he had some tranny's recently made.

Mercury Magnetics (or others) likely has one that will work but there is the 60, 100, 105, 180/190 so it depends on what you need.

He had some made to match the original in his llC?
I didn't realize a different transformer was used in each different configuration..or did you mean they used different transformers in the same model.All I remember is the transformer that went into Mark lll was a smaller one not as good as the one that went into llC. I was thinking just in case I need one some day.

 

[user 41014]

Here is the link to the thread but you can jump to the end for the recent tranny's he's had made.

https://boogieforum.com/threads/vintage-mark-style-pcb-and-chassis-kit.87172/

Iirc Jay went with the "100" clone in the kit for a 4 x power tube config.

The 60W and 180W ones are specific to those power sections but a IIC+ with 4 power tubes is going to be the 100 or 105 PT.

Some people, usually ones selling an amp that has one, say the 105 is the holy grail. But the 105 was made at a time when you could get STR 415's the 105 was designed for and the STR 454's then took over as tubes that could take the high plate volts of a 105.

With those tubes all but gone JJ is the only 6L6GC left that can take the 105 plate volts (tho not all 105's have super high PV's); or you are relegated to using the STR 425. (Same for the coliseums and early mono-blocks.)

So using the 100 PT to clone makes the most sense. Some prefer the 100 and some will say you are splitting hairs you will at best feel not hear.

 

[Jay Omega]

Here is the link to the thread but you can jump to the end for the recent tranny's he's had made.

https://boogieforum.com/threads/vintage-mark-style-pcb-and-chassis-kit.87172/

Iirc Jay went with the "100" clone in the kit for a 4 x power tube config.

The 60W and 180W ones are specific to those power sections but a IIC+ with 4 power tubes is going to be the 100 or 105 PT.

Some people, usually ones selling an amp that has one, say the 105 is the holy grail. But the 105 was made at a time when you could get STR 415's the 105 was designed for and the STR 454's then took over as tubes that could take the high plate volts of a 105.

With those tubes all but gone JJ is the only 6L6GC left that can take the 105 plate volts (tho not all 105's have super high PV's); or you are relegated to using the STR 425. (Same for the coliseums and early mono-blocks.)

So using the 100 PT to clone makes the most sense. Some prefer the 100 and some will say you are splitting hairs you will at best feel not hear.

The transformers I designed are based on the 105 PT and the SC152019B simul OT.

Also, the JP-2C has a “105” PT, so any tubes that run in his amp will run in an amp with a 105.

 

[Nick Athanasatos]

Here is the link to the thread but you can jump to the end for the recent tranny's he's had made.

https://boogieforum.com/threads/vintage-mark-style-pcb-and-chassis-kit.87172/

Iirc Jay went with the "100" clone in the kit for a 4 x power tube config.

The 60W and 180W ones are specific to those power sections but a IIC+ with 4 power tubes is going to be the 100 or 105 PT.

Some people, usually ones selling an amp that has one, say the 105 is the holy grail. But the 105 was made at a time when you could get STR 415's the 105 was designed for and the STR 454's then took over as tubes that could take the high plate volts of a 105.

With those tubes all but gone JJ is the only 6L6GC left that can take the 105 plate volts (tho not all 105's have super high PV's); or you are relegated to using the STR 425. (Same for the coliseums and early mono-blocks.)

So using the 100 PT to clone makes the most sense. Some prefer the 100 and some will say you are splitting hairs you will at best feel not hear.

So if my IIC has this 105 Transformer in it the new Mesa 6L6s tubes won't sound right in it ?
It is one of the later llCs a little before the + ones.
Cause I bought a IIC from a guy, original owner maybe 4 years ago.The amp looks very well taken care of but he changed the tubes which were in the amp like the year before he sold it to me (Sylvania) from the Mesa store in California thinking it best to change the old ones since they were in there so long.Anyway the amp didn't really sound great to me at all but it was in such good shape original owner very nice person I bought it.I figured it needs servicing after all these years.I haven't played it since I got it but just did a few days ago.
It was noisy ..a loudish humm ..lead ok but clean channel horrible.plus fan cable just kept falling out so had to use electric tape to hold it in place..So I called Mesa for an RA #
So question is..is it possible that the new Boogie 6L6 tubes are causing this thing to sound crappy ?
Thanks

 

[user 41014]

The transformers I designed are based on the 105 PT and the SC152019B simul OT.

Also, the JP-2C has a “105” PT, so any tubes that run in his amp will run in an amp with a 105.

Thank you for the correction. Is there a reason you have the "105" for the JP in quotes? I'm not familiar. What plate volts do those tend to run? Given the tube selection at the time I wouldn't think they went for high PV's.

Edit- what are the ones you had made testing at?

 

[user 41014]

So I called Mesa for an RA #
So question is..is it possible that the new Boogie 6L6 tubes are causing this thing to sound crappy ?

Any and all problems don't matter at all if you're getting an RMA from the man that is going to deliver you as close as possible to a new IIC+. When you look over the service notes you'll probably find that he rebuilds the old pots you can't get anymore and fixes things you wouldn't have a clue about it. The list was long on the marks he did for me this year.

 

[Nick Athanasatos]

Any and all problems don't matter at all if you're getting an RMA from the man that is going to deliver you as close as possible to a new IIC+. When you look over the service notes you'll probably find that he rebuilds the old pots you can't get anymore and fixes things you wouldn't have a clue about it. The list was long on the marks he did for me this year.

Thank you that's what we will do.
Perfect : )

 

[Jay Omega]

Thank you for the correction. Is there a reason you have the "105" for the JP in quotes? I'm not familiar. What plate volts do those tend to run? Given the tube selection at the time I wouldn't think they went for high PV's.

Edit- what are the ones you had made testing at?

The JP-2C high voltage is the same as a 105, but the other windings are different. Plate supply is slightly over 500V at idle, it will vary based on your tubes and wall supply. It functions as the original but they are not interchangeable. The PT I had made runs the same as a 105 or JP-2C.

There are tubes that can withstand 500V in practice, look at voltage ratings in data sheets. I avoid tubes that won’t publish data if I don’t go with MFG recommended tubes. Boogies are biased relatively cold which helps the tubes tolerate higher voltage even if you exceed published max ratings

 

[GJgo]

Here is the link to the thread but you can jump to the end for the recent tranny's he's had made.

https://boogieforum.com/threads/vintage-mark-style-pcb-and-chassis-kit.87172/

Iirc Jay went with the "100" clone in the kit for a 4 x power tube config.

The 60W and 180W ones are specific to those power sections but a IIC+ with 4 power tubes is going to be the 100 or 105 PT.

Some people, usually ones selling an amp that has one, say the 105 is the holy grail. But the 105 was made at a time when you could get STR 415's the 105 was designed for and the STR 454's then took over as tubes that could take the high plate volts of a 105.

With those tubes all but gone JJ is the only 6L6GC left that can take the 105 plate volts (tho not all 105's have super high PV's); or you are relegated to using the STR 425. (Same for the coliseums and early mono-blocks.)

So using the 100 PT to clone makes the most sense. Some prefer the 100 and some will say you are splitting hairs you will at best feel not hear.

The 105 is worth the most (theoretically because of the high plate voltage) but it doesn't make it the best. Of the 9 C+ I've had, the one with the best lead feels was a DR with the 105, and the one with the best rhythm feels was a SR with the smaller tranny. My least favorite was a X101. That said I think the tranny plays a minor role & it's much more about the sum of the parts. People have a tendency to assign value arbitrarily.

In addition, I can pretty much guarantee that you swapped trannys in an amp, re-biased so it's the same and reamped, there would be zero difference on the mic. What about the feels you say? Well I did this with a HR once & swapped from a 100 to a 105, and personally preferred it with the 100. Ask 3 guys & you'd get 3 different answers though.

 

[GJgo]

The transformers I designed are based on the 105 PT and the SC152019B simul OT.

Also, the JP-2C has a “105” PT, so any tubes that run in his amp will run in an amp with a 105.

According to Mesa they designed the JP tranny around the PT105, however I have a couple issues with this claim.

- The JP PT dimensions are the same as the X101 dimensions. (larger than the 100 & 105, but not as large as the 180)
- The (early) JP PT plate voltage is around 465 where the X101 is around 460, 100 is around 490 & the 105 is around 505pv.

So even if they did design the JP PT "like" they 105, the shape & PV is in line with the X101. They dropped the PV to run with any modern tube, and when it was released the current tube was the STR440.

Side note, the MkVII PT is the exact same Schumacher PT as they're using in the newer JPs. It's also oversized, and running 465pv same as the early JP PTs.

Long story short if I had any older Mark with a PT issue, I'd happily drop a current JP/VII PT in there.

 

[GJgo]

So if my IIC has this 105 Transformer in it the new Mesa 6L6s tubes won't sound right in it ?
It is one of the later llCs a little before the + ones.
Cause I bought a IIC from a guy, original owner maybe 4 years ago.The amp looks very well taken care of but he changed the tubes which were in the amp like the year before he sold it to me (Sylvania) from the Mesa store in California thinking it best to change the old ones since they were in there so long.Anyway the amp didn't really sound great to me at all but it was in such good shape original owner very nice person I bought it.I figured it needs servicing after all these years.I haven't played it since I got it but just did a few days ago.
It was noisy ..a loudish humm ..lead ok but clean channel horrible.plus fan cable just kept falling out so had to use electric tape to hold it in place..So I called Mesa for an RA #
So question is..is it possible that the new Boogie 6L6 tubes are causing this thing to sound crappy ?
Thanks

It has nothing to with sound, it's about reliability. For the 500+PV PTs it's safer to stick with:
- 415s
- TAD 6L6GC STR
- JJ 6L6GC
- The Tube Store Preferred Series 6L6GC
- Mesa's 5881s

All ones I've used long term in Colis, which run closer to 550pv.

In terms of sound, so long as the power tubes are healthy, matched & within a reasonable bias range it makes no difference. Reamping & level matching fleshes this out. There is an argument for the feel changing- for example to me the JJs feel more aggressive with less top end detail than the other 415 based 6L6s (Sylvania, TAS & TSS) however there's not a good way to quantify that since the mic doesn't pick it up.

 

[Jay Omega]

According to Mesa they designed the JP tranny around the PT105, however I have a couple issues with this claim.

- The JP PT dimensions are the same as the X101 dimensions. (larger than the 100 & 105, but not as large as the 180)
- The (early) JP PT plate voltage is around 465 where the X101 is around 460, 100 is around 490 & the 105 is around 505pv.

So even if they did design the JP PT "like" they 105, the shape & PV is in line with the X101. They dropped the PV to run with any modern tube, and when it was released the current tube was the STR440.

Side note, the MkVII PT is the exact same Schumacher PT as they're using in the newer JPs. It's also oversized, and running 465pv same as the early JP PTs.

Long story short if I had any older Mark with a PT issue, I'd happily drop a current JP/VII PT in there.

My JP-2C plate voltage is >500V, I don’t remember what year I got it but it has the magnetic components transformers.

I will guess that they use the same transformer for domestic / export, so all things equal you’d need your PT core to be approx 10% larger for the same performance on 50 Hz power.