Classic Tone Transformers ?

[eschertron]

I definitely got more low end punch (but not at all flabby) and noticeably more volume.
I don't quite understand the relationship between calculated power dissipation from the tubes and perceived SPL into free space. The 50W iron is making more SPL than the 30 iron, but the power dissipation is theoretically the same.

I'd like to think that if the new OT passes as little as 1 Watt of power (a dorsal-posterior-generated number) in a "new" part of the spectrum, maybe in the part that you can feel as well as hear, then that 1 Watt of acoustic energy instead of that 1 Watt wasted as heat in the OT would make a difference that you can sense. The tubes are passing the same amount of energy to the OT, and the OT is simply giving you "more".

[wizard333]

You can use a 50W Bassman OT in a Blues Junior or Deluxe Reverb if you want, you just wire it so the active secondary tap is the one for half the actual speaker impedance. 8 ohm speaker, 4 ohm tap puts the reflected primary impedance right in the range for 2 EL84s or 2 6V6s. Does it make a difference in sound? Some amps seem to benefit from bigger iron, some don't seem to care at all if you go from an OT the size of a walnut to one the size of a grapefruit. IMO there are more effective ways to spend your money if you're doing it for mod purposes. If you're starting from scratch or replacing a blown OT, by all means, go for the gold.

What bigger iron does seem to do, all things equal, is make the sound hold together better as the volume goes up, and keep the bass controlled as the volume goes up (way up). At lower volumes, it can be very hard to hear the difference.

[g1]

I don't quite understand the relationship between calculated power dissipation from the tubes and perceived SPL into free space. The 50W iron is making more SPL than the 30 iron, but the power dissipation is theoretically the same.

I'll use the analogy of the OT being the transmission between the engine (power tubes) and wheels (speaker). The amount of horsepower an engine makes is not the same amount as measured at the wheels. Sometimes a better transmission can cut the losses between the engine and the wheels.
The OT is not 100% efficient and there are losses which can be dependant on the OT size. With all else staying equal, a larger OT will often give a broader frequency range. Guitar amps are often rated for power at 1Khz. Yet most of the notes played are much lower. The high E string fretted at the fifth fret is 440Hz. So just because an amp is rated at 50 watts doesn't mean it is putting out 50W at all frequencies.
Likely your amp was being "choked" by an undersized OT, and with the upgrade, you are now delivering more power to the speaker at frequencies lower than the "spec" frequency. At the actual spec frequency they test the amps power at, you might not see any power gain. But if you did a/b tests at multiple frequencies, you would probably see an obvious difference.

[mikeboone]

Great discussion gents. Thanks for the analogies.

To Wizards point, I agree that just blindly starting with the OT for modding may not be the ticket. However, in my case the amp general tone, the feel, etc. were fine. I just needed more volume and low end punch. The PT is already the same iron that Orange uses in the 50W Rockerverb. The stock OT is a tiny little bugger. It sounds great and if I had bought this amp for a recording studio it would never have been a question. I had played one but not had the opportunity to really crank it, so I got caught short in my deal.

So with that said, I had the OT sitting there collecting dust so I gave it a shot and got lucky. And, yes Wizard, the big iron go me some volume but more importantly the stability. It holds together very nicely and there is no flub.

[big_teee]

Also I haven't heard discussed, is the classictone OT Steels?
Some models for a few bucks more have their improved M6 Steel.
It is supposed to run cooler, and have higher performance.
I am fixing to build a Fender Marshall type head(Farshall).
I'm going to use the fender PT, OT, and a Marshall 5 Hy choke.
I'm looking at the 18001 OT, because I plan on using 6L6s.
Fender Output Transformer, Super Reverb, Bassman, Concert, 4/8/16 with M-6 Upgrade
It is only a few bucks more than the 18009 with regular steel.
So I thought I would give the premium grade a try!

[Joe L]

My experience has been poor. My best friend and I built Deluxe Reverbs. He used the Classic Tone and I used the Mojo Heyboers. The amps sounded identical until you dimed them. Mine was musical but his had a crackling, harsh distortion in the high frequencies. We put it on the bench and everything looked fine. Since he never plays with much distortion, it was a non issue.

Next amp I built was a Marshall 18 watt clone. I used CT power and output. The amp sounded terrible with loud buzz even at lower levels of overdrive. I did a lot of investigation on the bench and determined it was crossover distortion that I was hearing. I took the info on the Paul Ruby zener mod and some input by Doug H and fined tuned the bias excusion causing the distortion. The amp could have been used at that point but I remembered my friends DR with the CT. So I ordered a custom Heyboer from GDS amps. From the first chord, you could hear the improvement, even at clean levels. It had that instantly recognizable vintage Marshall sound! I put the zener mod on a switch and both in or out were great sounding but different. I called it a Vintage/Modern switch That is where it stands today and the guy I built it for just loves it.

With all this said, there are so many good reports for the larger iron that if I needed a Plexi style OT transformer, I would give them a try. Not one person has complained about buzzy distortion.

Anyone need a CT 18 watt transformer cheap?

[big_teee]

My experience has been poor. My best friend and I built Deluxe Reverbs. He used the Classic Tone and I used the Mojo Heyboers. The amps sounded identical until you dimed them. Mine was musical but his had a crackling, harsh distortion in the high frequencies. We put it on the bench and everything looked fine. Since he never plays with much distortion, it was a non issue.

Next amp I built was a Marshall 18 watt clone. I used CT power and output. The amp sounded terrible with loud buzz even at lower levels of overdrive. I did a lot of investigation on the bench and determined it was crossover distortion that I was hearing. I took the info on the Paul Ruby zener mod and some input by Doug H and fined tuned the bias excusion causing the distortion. The amp could have been used at that point but I remembered my friends DR with the CT. So I ordered a custom Heyboer from GDS amps. From the first chord, you could hear the improvement, even at clean levels. It had that instantly recognizable vintage Marshall sound! I put the zener mod on a switch and both in or out were great sounding but different. I called it a Vintage/Modern switch That is where it stands today and the guy I built it for just loves it.

With all this said, there are so many good reports for the larger iron that if I needed a Plexi style OT transformer, I would give them a try. Not one person has complained about buzzy distortion.

Anyone need a CT 18 watt transformer cheap?

Why not go back to ClassicTone (Magnetic Components)?
Give them a chance to make things right.
Maybe there is a problem, and they might love to fix it so they could get good press instead of bad?
T

[bob p]

My experience has been poor. My best friend and I built Deluxe Reverbs. He used the Classic Tone and I used the Mojo Heyboers. The amps sounded identical until you dimed them. Mine was musical but his had a crackling, harsh distortion in the high frequencies. We put it on the bench and everything looked fine. Since he never plays with much distortion, it was a non issue.

by any chance did you do the obvious experiment -- to swap OT between the two amps? although it's very easy to blame an OT when it looks like those might be the only obvious differences in the amps, it's important to consider other variables. when two homebrew amps that were built by two different people sound different, it can be pretty hard to determine exactly where the problem lies. I'm not trying to bash anyone's amp-building skills, so please don't take this the wrong way.

Next amp I built was a Marshall 18 watt clone. I used CT power and output. The amp sounded terrible with loud buzz even at lower levels of overdrive.

I might be in the minority, but I'm one of the people who thinks that the stock 18-watter isn't a good platform to assess sound quality of other components like OT. all 18-watters start off hampered by a circuit whose design inherently has problems with buzzy overdrive, crossover distortion, and ugly grid conduction. The original Marshall 18-watt circuit was a pretty poor design (JMHO) and it needs some major attention to get rid of the objectionable distortion. The Ruby mod is a good place to start, but there are some other things that can be done to help -- ChuckH has written a lot on this subject, and my experience has been that his recommendations are spot-on. As an added endorsement, at least one major amp manufacturer is now selling a highly successful EL84 amp that incorporates most of his recommendations! (except the zener mods)

It's interesting to hear that you liked the Heyboer so much more than the ClassicTone. I've never compared the CT 18W Marshall transformer to other transformers, but I have heard people say that the 10W Hammond sounds significantly better than the Heyboers in that application.

BTW -- I do like your idea of putting the grid zener mod on a switch to demonstrate how well the Ruby mod helps fix some of the 18W problems.

Anyone need a CT 18 watt transformer cheap?

Is that one of the M6 transformers? How cheap is cheap?