OT A/B test

[Tonegeek]

I did another A/B test this morning. I recorded the test but honestly, even listening with headphones the recordings did not pick up the differences between the transformers so I will not be posting them.

All test are in OD mode

First pass was with Mid boost on and a low drive setting so its breaking up with some crunch. My impression is that there is not much difference between the 2 transformers except that after going back and forth I tend to conclude that the MC still exhibits slightly more high end.

second pass is with mid boost and some PAB (on a BM you just lift the stack from ground by a certain amount, in this case 56k). I also kicked the drive up so now the amp is louder and with more singing, vowelly compression. Now I am noticing that high end in the MC readily. On the MM side the highs are even with the rest of the spectrum and there also seems to be some kind of pleasing mid thing going on. There is a bit more mid definition that is Marshally in character. Back on the MC side I was able to remove some highs with the presence knob and this helped balance things out. Both of the transformers sounded good, but I have to admit, just playing by myself, that I slightly prefer the sound of the MM in this case where as before I had no preference. As someone pointed out though, its a different ballgame when the rest of the band is blasting away. I might miss that MC high end in that case.

I did not do a blind test where I was the listener, but my wife who has a great ear did the listening while I played and did the switching. She did not know which tranny I was on during the test. Her comments were that one of them (MM) sounded "fatter- more full" and the other one sounded "Sweeter" (MC). This was a lower volume test.

Finally, I also used a signal generator and O-scope to look at the output of each tranny and at higher frequencies the MC was putting out slightly more voltage which confirms what I was hearing. I don't have any numbers; it was just a relative look at each one. Also in an earlier comparison, what I described as the MM having more girth, needs further explanation. Both transformers have strong bottom end that holds together. The MM does seem to present a bit more detail, on power chords. On single notes its a toss-up. I will get my drummer in sometime this week to try the tests again under live situations.

[hitchcaster]

thanks ive been wanting to do this forever! MM has one of these switchers, but i don't know what they have listened to.. ive done lots of A/B's soldering fast but never this way.. the only thing that is a problem is the positioning of the OT.. did you flip it over when you listened to it and try moving it around? really the one thats attached is going to be in the sweet spot.. id put the spare in in the same spot in line but farther out.. check it out, i think you'll hear it moving it around. in the past ive taken advantage of MM's uncut leads return policy and bought a few options on OT's for an amp I'm doing.
thanks!

[Tonegeek]

thanks ive been wanting to do this forever! MM has one of these switchers, but i don't know what they have listened to.. ive done lots of A/B's soldering fast but never this way.. the only thing that is a problem is the positioning of the OT.. did you flip it over when you listened to it and try moving it around? really the one thats attached is going to be in the sweet spot.. id put the spare in in the same spot in line but farther out.. check it out, i think you'll hear it moving it around. in the past ive taken advantage of MM's uncut leads return policy and bought a few options on OT's for an amp I'm doing.
thanks!

I never considered that the position of the OT would affect the tone. It is reasonalbe to assume that you can gain a bit of noise reduction by placing the tranny a certain way in relation to the PT and Choke. Have you done studies on this?

[talbany]

Sounds like the difference is in the interleaving being that MC are paper style could be the source for the slightly brighter tone..I think MM uses there own special blend type of oxygen free copper wire..The MM are also very consistent sounding X formers and seem to have a deeper throat..The MC are more like a good sounding tweed type transformer to my ears..(paper interleave)
Cool test..

Tony

[xtian]

It is reasonalbe to assume that you can gain a bit of noise reduction by placing the tranny a certain way in relation to the PT and Choke. Have you done studies on this?

This is proven and easily observable. I now perform the "headphone trick" to place PT and OT on the chassis where the PT induces the least amount of hum in the OT.

[nix]

imho once the drummer, bass, and keys come in, does it matter? If one has to struggle to hear a difference in an intimate setting then I would go with the less expensive one.

In my experience, quite the opposite is true. When placed in a mix (stage or studio), the subtleties are considerably more evident, and therefore, pretty important.

[Tonegeek]

It is reasonalbe to assume that you can gain a bit of noise reduction by placing the tranny a certain way in relation to the PT and Choke. Have you done studies on this?

This is proven and easily observable. I now perform the "headphone trick" to place PT and OT on the chassis where the PT induces the least amount of hum in the OT.

Sorry I had an unclear antecedent. I meant had the poster done studies on placement in relation to the TONE of the transformer. I am aware that orientation can reduce hum. thanks.

[briane]

cool test.

I know probably not one on hand - but I'd be more interested in how the dynaco 470s stacks up against the MM. Only because I have 2 almost same great builds in the back room - one dynaco and one MM - lets just say the visitors sh*t their pants when they play the dynaco - not so much with MM.

Wish I had considered this a few years ago - now I'm not touching those amps with an iron - its just too much work.

-b

[Colossal]

I know probably not one on hand - but I'd be more interested in how the dynaco 470s stacks up against the MM. Only because I have 2 almost same great builds in the back room - one dynaco and one MM - lets just say the visitors sh*t their pants when they play the dynaco - not so much with MM.

Do you mean a real Dynaco A-470-S vs. Mercury's version of the A-470-S? or Dynaco vs. some other Mercury OT?

I know for a fact that Mercury's A-470-S offering is a clone of an original Dynaco and I have used this OT in numerous amps and it is a fantastic sounding piece.

[briane]

Do you mean a real Dynaco A-470-S

No - triode elsectronics - cause it really is the bomb.

[LeftyStrat]

cool test.

I know probably not one on hand - but I'd be more interested in how the dynaco 470s stacks up against the MM. Only because I have 2 almost same great builds in the back room - one dynaco and one MM - lets just say the visitors sh*t their pants when they play the dynaco - not so much with MM.

Wish I had considered this a few years ago - now I'm not touching those amps with an iron - its just too much work.

-b

What kind of build are you using the 470 on? I'm really curious, since I have a triode dynaclone, and three original 470s with cloth leads in my parts bin, and I'd love to put them to proper use.

[M Fowler]

I have used the Triode A-470S iron for TW Rockets, Marshall JCM800 circuit, and other builds great transformer.

Mark

[hitchcaster]

thanks ive been wanting to do this forever! MM has one of these switchers, but i don't know what they have listened to.. ive done lots of A/B's soldering fast but never this way.. the only thing that is a problem is the positioning of the OT.. did you flip it over when you listened to it and try moving it around? really the one thats attached is going to be in the sweet spot.. id put the spare in in the same spot in line but farther out.. check it out, i think you'll hear it moving it around. in the past ive taken advantage of MM's uncut leads return policy and bought a few options on OT's for an amp I'm doing.
thanks!

I never considered that the position of the OT would affect the tone. It is reasonalbe to assume that you can gain a bit of noise reduction by placing the tranny a certain way in relation to the PT and Choke. Have you done studies on this?

yeah, whenever i do an amp i leave the OT leads long. hooked up but ill cut them later. .. don't attach the trannie, and have the chassis flipped over...i just move the OT around and play and listen. no, its not just "more noise here, less noise here".. it sounds different in different positions.. you'll find a spot that sounds the most "open". if you have good ears you can notice if you move the trannie just the smallest amount it will make a difference.. also, depends on what trannie you use, of course. so theres no "magic spot" for all trannies, but theres a ballpark magic area which is usually where they normally go in well known amps. never bothered with the headphone trick because i never play/listen to the amp that way .. also, sometimes things that give the least noise, don't always sound the best to me.

[odourboy]

You did the test that I've always wanted to do... congrats!

I did a similar comparison (testing the same trannies as you) only I used the power section of two different amps with matched (as best I could) tube sets and cabs and used the pre-out form a single amp to switch back and forth between the power sections. I came to similar conclusions, but since there were many variables in my test, I never posted any results.

I decided that MC would suite me fine for most builds since i felt the subtle differences I heard could probably be dialed out using tone controls or other tone shaping components in the build, so there was really no compromise in going the cheap route. Just one guy's opinion!

[briane]

What kind of build are you using the 470 on?

well - as you know as well as I this community has 'progressed' in its naming of builds over the last 5 years- I dont pay attention to hype - so I call it the # 124 as it used to be called- but I think you all are calling it the 102 now - basically a moded version of the normster & dog ears (and others) original dlite build. 6v6 or 6l6.

Like I say - I just find the best and forget the rest - so theres really only one dumble circuit in my book. - though a lot of variations on that one.

hey lefty - since your in seattle - if you ever want to take a listen pm me.