Thinking about stocking Mercury Magnetics transformers

[jojokeo]

As for the Hammonds, I've found that some of their 2XX series of PTs run very hot, and they can be sucseptible to heater noise being coupled to the B+. On a couple of amps with the 276X PT, I've had to use a separate heater tranny to get the noise down.

The 3XX series is better built, runs cooler, and seems to better shielded from heater noise.

Ken - do you notice this heater coupling noise:

• while running the amp at any power level?
• only at or near full power?
• on all 200 series of PT's or only with a few?
• I'm taking it that you've verified it's from these PT's exactly? (replaced them with some thing else and the noise went away OR you simply left it in and got another heater tranny to resolve?)
• you're sure that your other iron is placed properly & not too close to each other, etc.?
• have you tried elevating your heaters w/ DC? (did this help?)

Thanks-

[Ed_Chambley]

This will confuse no one because very few read my posts, but I send thanks to those who show the love.

Well, I do...and the biggest problem with that is that I can't un-read them

8 inch board, 8 inch board.  Sluckey is up to something.  It is really amazing if it is not any wider.

Now unread this.  Maybe he will tell you.  It is a BIG secret he is going to spring on us but he has to do some roofing first.

He is going to use MM even though there is no different.  What a Knucklehead, right?

[Ed_Chambley]

As for the Hammonds, I've found that some of their 2XX series of PTs run very hot, and they can be sucseptible to heater noise being coupled to the B+. On a couple of amps with the 276X PT, I've had to use a separate heater tranny to get the noise down.

The 3XX series is better built, runs cooler, and seems to better shielded from heater noise.

Ken - do you notice this heater coupling noise:

• while running the amp at any power level?
• only at or near full power?
• on all 200 series of PT's or only with a few?
• I'm taking it that you've verified it's from these PT's exactly? (replaced them with some thing else and the noise went away OR you simply left it in and got another heater tranny to resolve?)
• you're sure that your other iron is placed properly & not too close to each other, etc.?
• have you tried elevating your heaters w/ DC? (did this help?)

Thanks-

Great question.  I have used a few 2xx Hammonds.  On my last build I used one and it is very quiet.  This is the AC15, however the ground scheme Sluckey came up with was J&J.

Were you maxing out the PT cause I have always heard they are overbuilt.

[jojokeo]

I've used them in at least 4 builds and they are quiet BUT on one of them - when I ramp up the power to most to all of the way - I get some crazy coupling issues. Thankfully the amp reaches actual full power before this noise threshold occurs and I don't go past 4 or 5 anyways with it. It's got plenty of power/volume by this point.

[SILVERGUN]

He is going to use MM even though there is no different.  What a Knucklehead, right?

Yes....
I'll give him a pass this time

I'd use MM too if it was laying around....you never know,,it might sound ok 
....couldn't sound worse than that OEM crap 

[sluckey]

This is for you Ed. Now I'm dropping out of this thread before I get booted out!

[Ed_Chambley]

This is for you Ed. Now I'm dropping out of this thread before I get booted out!

What crap is this?

Post this and run and hide.  Go ahead and untangle your panties and show me the real board.

When I get embarrassed about posting too much it doesn't last long once I realize that it is not my fault.  I am gonna look over my layouts and see if I can see where all the wasted space is.

[Ken Moon]

Here's the schematic and tranny layout of the amp where I first saw the problem:




I saw a 120Hz ripple start to appear on the scope at just over half power into a resistive load. You can hear the hum start to develop pretty easily if you crank it through an attenuator.

The heaters are elevated 70V in this design (with 120V AC mains input).

It went away completely when I substituted a small shielded Hammond 6.3VAC/4ACT filament tranny, so that's what I've done on all my amps since.

My newest 2x6V6 amp is using a 372FX PT, and it is cool and quiet.

[Ed_Chambley]

Oh, sorry Ed. Wrong board. Don't cry.

Wiping my tears now.  You really are a smart feller or 

Thanks! 

I see how you did it.  Looks like you learned something from the AC15 layout.

[macula56]

i have used the MMs and Classic Tone stuff with good results. Both seemed a bit pricey to me but they are both good products. I have also used Weber stuff and transformers that i bought here. They all work just fine as far as i can tell. i haven't heard any real discernable differences.

[Stankfut]

Doug, I won't presume to tell you how to run your business.....buuuuttttt


How about you offer MM as a premium brand for those with deep pockets, and Mojo for the rest of us schlubs? Best of both worlds, unless they want you to offer their product exclusively. I think you might be able to do that without tying a lot up in inventory 

[EL34]

Doug, I won't presume to tell you how to run your business.....buuuuttttt


How about you offer MM as a premium brand for those with deep pockets, and Mojo for the rest of us schlubs? Best of both worlds, unless they want you to offer their product exclusively. I think you might be able to do that without tying a lot up in inventory 

Yeah, that's what I was thinking of doing
Mojo's are not that cheap either


New Sensor had the best prices for iron for the longest time

[lego4040]

I don't build enough amps and I'm no expert in this field, I follow your advice when i have a question. If  I can get away with a economical PT and save so I can spend that extra money on a OT where all that mojo comes out i would be inclined to do so. I've been reading and looking at those Edcor Trannies as well and they have been getting really good reviews. I don't care if I have to wait to have one built and the speed I oh it's not a issue. For the price of one Mercury I can get a set from Edcor or ClassicTone tho. From Doug's view it's business and are the numbers gonna make it worth while. From a hobbyist view strapped for cash, he's gonna bargain shop. If I can get all I need from one place and save on all that shipping, that's important. What ever you decide Doug I know it's not going to be a crappy product. I wish I got into this hobby a long time ago

[HotBluePlates]

Regarding price, there have always been "cheap transformers" and "expensive transformers".

I found old transformers catalogs with price lists at Audiophool. Those figures can be converted using an inflation calculator.

A cheapo Triad transformer for push-pull 6V6's (maybe the S-21A, probably better than the type Fender used) was listed as $5.80 in a 1952 Triad catalog. That would be $52 today.

An excellent UTC 20w OT for push-pull 5881's (the HA-136) was $18.00 in 1960, or $144 today.  That was a good transformer, but short of UTC's top-of-the-line LS-35 (35w output from push-pull EL34's), which was $24.00, or ~$193 today.

Transformers for tube use were in vastly higher production then, so greater competition probably pushed prices downward. I think there's a place for a budget transformer option, and for Mercury's premium option (partly more expensive due to the claimed replication of original transformer characteristics).

[clyde]

Just to add my .02, some friends and I did a blind test a few years ago of OT's in an AC30-type build.  I clipped one of 4 transformers in circuit while a friend played and another listened.  We used a Mojo, Edcor and 2 MM transformers.  After going back and forth to get acquainted with each, it was decided that the 2 MM's were best.  It wasn't subtle. 

[EL34]

MM guarantees you will here a difference and they have a 10 year warranty
That's a confident company there.


I have begun to add some Mojo tranny's to my stock
They are Heyboer


Not much not to like about thst

[navdave]

I agree the Edcor stuff is great but the turn around time is a big bummer. I've used the Classic Tone Twin Reverb
OT for a twin type clone build and it sounds great running a quad of 6l6's with about a 535v b+ for over the last two years. Next build is gonna be all custom wound Heyboer stuff.

There is no way I would buy a MM transformer when there are great sounding options that are sooo much cheaper.

I've used Hammond, Heyboer, Classic Tone and Edcor. They have all sounded fantastic. My preference is Edcor but those are made-to-order and you have to wait about six weeks. It certainly helps that Edcor looks better than all the others and is cheaper than all the others, but they also sound fantastic... and they have been around for a LONG time.

Now, if you could somehow manage to be the only person who sells Edcor iron "off-the-shelf" I think you would make a tidy profit indeed.

[Fresh_Start]

I built two nearly identical Princeton Reverbs, one with MM and one with Doug's transformers. I couldn't hear any significant difference and did play them side by side. However, both times I've built an amp for someone else they specifically requested Mecury Magnetics iron. Any boutique amp builder who uses MM iron mentions it. Are MM transformers worth the extra cost?  "Yes" if the guy playing the amp thinks they are.

Doug, if you can handle two lines of OTs, then please add some MM.  If only one line, please carry something more cost effective.

As far as which MM OTs to start with, I'd suggest 5E3, AB763, and a Plexi. 


It would be nice if you carried a couple of basic Hammond OTs for single-ended amps.

[EL34]

I am adding Mojo tranny's to stock right now
They are Heyboer's and very nice quality


Plus I can sell them at the 100 piece price and save you guys some $$$


MM possibly some day


CT and Edcor, I doubt it since they sell direct at less than retail
There's no incentive for merchants for thos two companies

[lego4040]

  i spent hours yesterday reading up on the companies people have been name dropping hear and I got a headache. I will buy one of those Mojo OT for your Plexi

[Voxbox]

Hi All,

This thread has been going a while, but I'd like to add my compliments about my experiences with MM.

All too often folks complain about poor service and so on, so its refreshing to deal with someone as helpful as Patrick at MM. With myself he's been always friendly and helpful with advice and with pricing too.

I bought a replacement 125A29A OT (and PT) for a 1960 Vibrasonic recently. Unfortunately the wrong (Fender) OT was in the amp as the original had been replaced with one for a 1972 VibrOsonic that has 4 x 6L6s rather than the two 6L6s of the VibrAsonic.

Although both OTs are rated at 100W, its not really a fair comparison, however I have to say that the difference is NOT subtle. The MM results in a lovely deep, rich, complex bass. It is not plummy or woolly sounding at all. The top end is not harsh and the whole sound can best be described as being musical. It's extraordinarily challenging to convey in words what something sounds like. One mans "harsh" is another man's "bright" for example. In comparison the Fender was bass-light and the top end was a bit harsh.

However I do have a set of MM trannies for a 5E3 so I'll be able to compare these with the ones I bought from Doug many years ago.

The only thing about MM and others is that they are all made in the USA, so shipping over here to the UK makes it really expensive with the shipping charges, customs, VAT and handling charge.

I would have loved to have tried OTs from different manufacturers such as Cleartone as I had heard good things about them from another Vibrasonic owner who used one in preference to MM, but the shipping charges just killed the possibility of that.

Anyway hats off to Patrick for providing such a good service. Thanks mate! 

Cheers, VB