Choosing transformers: is mercury magnetics a snake oil scheme?

[Jazz P Bass]

I had a customer bring in a Fender Deluxe Reissue.
Not too sure who fleeced this guy.
MM power transformer.
MM choke.
MM output transformer.
Weber speaker. 12F150B.

To be honest, the amp sounded great.
Which I would attribute to the Weber.

[Justin Thomas]

Bamboozled by marketing copy? I remember a thread a while back here, arguing that maybe bigger isn't always better for an OT, at least... Something about a Bassman 100 OT in a TR or TR OT in a Bassman 100... Anyway, the larger OT reportedly made the lows fuzzy and wooly, even for a bass? So the whole "Fat Stack" thingy doesn't fly with me. I say, don't be cheap, don't splurge, you're good to go.

I could try the experiment myself, as I own both a Bassman 100 and a TR tranny set... My 67 Bassman also has a TR OT in it, & I found out my Concert apparently has the same PT as a contemporary Twin? Oh well, I should get hacking...

Justin

[nsubulysses]

They said in the ad that sometimes you should replace a "tired" old choke. This company should be sued and put out of business. They still don't publish any specs on their site because it's not aimed at tech people which would see through their idiotic marketing bluster in an instant. They are trying to attract the "cool, rock guitar guy," or the endlessly searching tone hound-type. So basically people that don't know how to change a plate or cathode resistor and actually adjust the sound of their amp


Edit: two seconds on their site and I come across this. I remember I saw this a couple years ago and also got mad:

The Phenomenon of Ear Fatigue
Did you know... that ear fatigue is related to poor transformer quality? If while playing (or listening to someone play) through an amp you find yourself tiring easily, or the experience seems unpleasant… you are experiencing the tell-tale signs of ear fatigue. It is nature's way of telling you that something's wrong. In nature all sounds are composed of layers of frequencies producing all sorts of harmonics and distortion. Ear fatigue is caused by information commingling with non-musical, unnatural noise that "beats up" your internal mechanisms. The mechanisms that make your hearing possible are working overtime trying to separate the desirable from the less desirable sounds. It's the output transformer's job to emphasize the even-order harmonics and make tones more musical, appealing, and less fatiguing. There's no short-cut to building a quality transformer. The result is less effort by your ear to receive this information.

I am no doctor but I thought ear fatigue had to do with high SPL for extended periods of time. Not if the amp had a MM transformer or not

Edit again: I am laughing thinking of EVERY classic amp that everyone loves the sound of that doesnt' come with a MM transformer. Do any famous, legendary, desirable, etc amps actually come with MM transformers?

[Chuck H]

I actually tried above not to and didn't want to turn this into another bash MM thread, but yeah, That one always pissed me off. That's a big ,smelly load of horse shit. Totally made up and inaccurate regarding either ear fatigue or transformers in any way. For one, ear fatigue is not related to the harmonic relationship of the sound. (<period) And B, transformers have absolutely no ability to filter odd or even order harmonics selectively. (<period) This isn't just hype, it's a blatant lie with the intent to mislead and then profit from it. Which, if it's not, should be illegal. On what grounds you prove that I don't know but it would be a kick to see the money grubbing maggot who wrote it try to explain themselves when the only accurate answer could be "I made up a lie to get more of other peoples money".

[Leo_Gnardo]

Do any famous, legendary, desirable, etc amps actually come with MM transformers?

2-Rock? Got $10,000? Meanwhile Dumble goes shopping for iron at Ruby/Magic Parts. Another little-heard-from source. I've gotten lots of transformers from them. If it's good enough for HAD, it's good enough for me. And my customers.

[catalin gramada]

Think you missing that: https://m.youtube.com/watch?v=0UUWqQy-Kgg&t=145s
It seems You throw the money on the window if buy a MM PT without a MM 30 bucks power cord

[nsubulysses]

5,000,000 repairs between everyone on this forum and no one has troubleshot a badly working amp and then eventually realized, "we need to replace the choke. It's tired and old."

SO, if MM gets bashed, it's not like we were trying to go out of our way to do it. It's just that...........what they say makes no sense
It seems to be a brand for people who don't know better, or better yet want to believe.

All that aside. I'm not saying their transformers are good or bad. I just dislike everything that has to do with their image and marketing.

My own anecdotal experience is when prototyping amps use Hammond. They are awesome, and their product line will allow you to make almost any amp you want with off the shelf transformers. When you want to make more then one amp, use Heyboer. I don't notice their transformers to sound ANY different from same amps with Hammond iron. And Heyboer will make 1 transformer for you or 1,000, built to your spec. Even if you just ask them to make "this hammond PT and that hammond OT" they will do it. They will be about same price as Hammond if you buy 1 set. If you buy 5 or more of the same transformer they will be about 15% cheaper than Hammond. I'm sure you can get better price breaks with bigger orders but I've never ordered more than 5. If you want to be cheap or if it just fits your project, use Classictone/Magnetic Components. Some amps that I've built with Classictone iron made me say, "WHAT! does this amp actually sound slightly better than same amp with Hammond/Heyboer transformers or is it just me!??!?!" At this point you are analyzing minutia and it may or may not be true, but it is up to the listener to decide if they want to believe!

Exact same amp built with everything exactly the same except transformer brand still has every component tolerance to take into account, plus pots are notoriously not exact so treble on 6 on one amp is not necessarily the same as treble on 6 on another amp, so it's really difficult to actually tell, even if amp circuits are identical.

So in conclusion I consider those 3 brand to be stand up products I've always had good results with and I dislike MM even though I've never used them. I think Hammond/Heyboer/Classictone also intalled all the mojo in the iron but they just didn't talk about it incessantly to lure in obsessive tone seeker types

[tedmich]

Think you missing that: https://m.youtube.com/watch?v=0UUWqQy-Kgg&t=145s
It seems You throw the money on the window if buy a MM PT without a MM 30 bucks power cord

Oh I forgot they made high fidelity power cords, and a bargain compared to the real audiophools!

Can I market a too small cord (maybe 22 AWG) as an "extra hot" cord for extreme players? Firewire 2.0??!

[Leo_Gnardo]

I think Hammond/Heyboer/Classictone also intalled all the mojo in the iron but they just didn't talk about it incessantly to lure in obsessive tone seeker types

And thank hevvins for that! Geeze I want the job being the mojo installer... do I need a kollidge degree or what?

Speaking of mojo, where do Mojo, and while we're at it Hoffman get their iron? I think it's Heyboer.

[nsubulysses]

I know heyboer makes a lot for mojotone. And I know they also make the ampeg replacement transformers fliptops sells. You don't even have to request they add the mojo in, they just do it without even asking.

Anything with the sticker on it with serial number listed as HT-xxxxx is a Heyboer Transformer

[J M Fahey]

So far I had been neutral about MM
As in: transformers look good, nobody complains about them, if anything they are praised, price is too high compared to competence or average but my Merchant mind thinks: IF they can add some marketing and charge extra, fine with me ... THAT is the purpose of Marketing, advertising, etc. , a normal part of day to day business.

BUT when they start POISONING people´s minds with crap properly described as : "This isn't just hype, it's a blatant lie with the intent to mislead and then profit from it. " and now I am pissed off, so from now on will actively burn any claim they make in every Forum I find them. As simple as that.

[nsubulysses]

The real question is should the cathode capacitor of V1 gain stage be 1uF or 1.5uF. I thought it was 1.5uF but i recently found that it should be 1.2uF for best tone result in my application (not joking). Maybe 1.25uF would be better but I haven't tried yet (joking).

Listening to the amp constantly for over 2 years I thought 1.5uF was PERFECT but then I mailed one (coincidentally this one had Hammond PT, Classictone OT cuz that's what I had around) to a golden ears recording engineer to demo and he said the bass was too loose/flubby and suggested I reduce bass response early in the preamp to fix it. He hypothesized that "the sound of metal" was a starved bass response early in the preamp and then more bass added later in the preamp so it can still be full sounding but remains tight and articulate on pick attack due to limited bass early on. He is right. I did not even know til he told me it had too much bass. now I agree, reducing 1.5uF to 1.2uF it still sounds thick and full but the response on pick attack is better -- it has more clarity and presence, and sounds more biting and aggressive. 1uF is too low, it's thin sounding when cords ring out and when doing chugs, and a bit too harsh on pick attack. Strange coincidence, this is a parallel 12AX7 gain stage so 1.2uF cathode cap is equivalent to .6uF cathode cap on regular gain stage, DANGEROUSLY close to Marshall value of .68uF cathode cap. So the studio engineer is unaware of this but he is basically telling me to adjust my amp more towards typical marshall values for a better sound Damn! just when I thought I was reinventing the wheel!

1uF vs 1.5uF will change the sound more than what brand transformer you use, IMO, and that's just 1 minor component value change to 1 component out of dozens or hundreds in an amp. All amps with 1.2uF cathode cap will sound better than all amps with 1.5uF cathode cap regardless of what transformer brand the amps have because one will have a more flubby/loose bass response on pick attack and the other will have just the right amount of woof and cut for metallic playing. Well, in some peoples opinion at least

Of course Chuck thinks it should be 25uF for best hum result but that's a whole nother story. i never heard anyone say, "wow that amp had the best sounding lack of hum I've ever heard!" Must have been heavy in even order harmonics if it did I would guess.

Sorry guess i am going way with my tangent. I think the best circuit sounds the best

[Chuck H]

Of course Chuck thinks it should be 25uF for best hum result but that's a whole nother story. i never heard anyone say, "wow that amp had the best sounding lack of hum I've ever heard!" Must have been heavy in even order harmonics if it did I would guess.

I absolutely DO But it isn't just for hum. Most of the (production) cascade preamps that employ a partial bypass first gain stage are also employing DC filaments now. I recently did some ear testing before changing one of my long standing designs. This amp does NOT suffer from any filament related hum. I arranged a 4pdt switch with a 3.3uf bypass cap, a 22uf bypass cap and associated circuitry to "correct" the frequency content after decoupling. I tried several different 12ax7's in the first position just to rule out the probability of a noisy tube influencing the test. The results were consistent and the fully bypassed cathode was always quieter, but it wasn't hum that was eliminated because, as I mentioned, this amp doesn't hum. Further, the noise wasn't 60Hz and it wasn't a sine wave. More like a low frequency hash. Since I have limited bench gear for testing such things I can only guess that it's some sort of emission noise inherent to elevated tube cathode circuits. It's therefor my experienced opinion that the trend toward partially bypassed cathode circuits in modern amps began with the genre of amp modification and hasn't been adequately examined with respect to this noise consequence.

I still use partially bypassed cathodes for later stages when it gives me what I want. The noise consequence in these later stages doesn't seem significant.

Thought I wouldn't respond

But I digress now in the interest of not entirely derailing the thread. I enjoyed your storied explanation of the issue above and agree that these elements of design are eminently more important than whether you choose a Hammond or a MM transformer.

[SoulFetish]

I've probably softened my stance on MM a little bit with experience. What you need to know if you are ordering a drop in replacement is, sometimes they fit (a little snug), and sometimes you need to be prepared to do some metalwork; and professional quality metalwork if you want to keep your amp from looking like it was butchered by a hack.
I think they are often overpriced and a comparable transformer can be had by the other manufacturers mentioned above. But our shop is a Merc dealer, so for me personally, often MM can actually be a better option.
They traditionally provide NOTHING substantive in the way of technical information, so they aren't really an option for me at all when designing and amp.
I do think they pedal some bullshit in marketing their transformers. But I will admit, that in an actual blind listening test for one particular amplifier, I NARROWLY chose the Mercury output transformer over Heyboer in a shootout of 4 transformers (I think?). Let me see if I can find the link...
sorry, it was 3 transformers. See for yourself:
http://www.channelroadamps.com/articles/ot_shootout/
I was actually surprised by the results. I wanted to have a douchy attitude about MM, but there you have it.

[Chuck H]

I've probably softened my stance on MM a little bit with experience. What you need to know if you are ordering a drop in replacement is, sometimes they fit (a little snug), and sometimes you need to be prepared to do some metalwork; and professional quality metalwork if you want to keep your amp from looking like it was butchered by a hack.
I think they are often overpriced and a comparable transformer can be had by the other manufacturers mentioned above. But our shop is a Merc dealer, so for me personally, often MM can actually be a better option.
They traditionally provide NOTHING substantive in the way of technical information, so they aren't really an option for me at all when designing and amp.
I do think they pedal some bullshit in marketing their transformers. But I will admit, that in an actual blind listening test for one particular amplifier, I NARROWLY chose the Mercury output transformer over Heyboer in a shootout of 4 transformers (I think?). Let me see if I can find the link...
sorry, it was 3 transformers. See for yourself:
http://www.channelroadamps.com/articles/ot_shootout/
I was actually surprised by the results. I wanted to have a douchy attitude about MM, but there you have it.

Terrific test I narrowly chose the Weber OT for it's more focused midrange. But I think that's because the test amp was rather brash sounding, so that contribution helped that particular amp. Otherwise the Mercury had a more open, but still full sound and may have been the best with , say, a Marshall type amp. Take that Triode OT up on an overpass and toss it at a car