MQ Mania

tsingle999 · 14117

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Offline tsingle999

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on: November 01, 2012, 03:05:24 PM
1. i decided during the hurricane to upgrade the iron in my SEX amp instead of sitting around with no power. I purchased some ni outputs from a member awhile ago. I knew i had also purchased m4/ni before that. So when i dug it all up i remembered i had also purchased m4 outputs a long time ago at a deal too. Currently have m6 under the hood. So should i just put the nickel in and live large or is there some way to configure a separate chassis full of 4 types of MQ iron that could be switched?

2. Continuing this idea i have tfa2004sr ni and an m4 along with tfa2004jr ni, a cobalt and an m4 with a cobalt pinstripe. I wouldnt mind building a switchable MQ tfa chassis and plug my sr45 monos into it. Is this just a crazy idea???

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Offline Paul Birkeland

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Reply #1 on: November 01, 2012, 05:25:17 PM
Switching iron seems exceptionally iffy, you have to consider that there's has to be B+ on the switch, and when you switch to the next set of iron, you will probably draw an arc each time as the parafeed cap charges.  Also, I would think you'd want to switch both legs of the plate chokes, maybe just one end of the primary on the output transformer, and the secondaries.  This is a 5 pole switch, or a bunch of smaller switches...

I'd stick the nickel iron in the SEX amp, and see if that member who sold you the M4 iron will buy it back ;)

I think the TFA-2004jr/ni is best suited to the SR-45, but that's PJ's baby,  so he may have other ideas.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline xcortes

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Reply #2 on: November 01, 2012, 05:42:51 PM
I have an m3 Sex and a Ni one. The m3 is very special...

Xavier Cortes


Offline Grainger49

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Reply #3 on: November 02, 2012, 02:14:22 AM
I think you need to sell some iron after making the decision.  Much the same as I need to sell some film capacitors.
« Last Edit: March 24, 2013, 07:15:41 AM by Grainger49 »



Offline Paul Joppa

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Reply #4 on: November 02, 2012, 07:47:19 AM
... Is this just a crazy idea???
Yes, of course it's crazy. What's your point?  :^)

I did that a long time ago, before we started using parallel feed. PB is right, the switches arced like crazy and I threw them out after the experiments were done - they were scorched and pitted. Really, I should have switched the amp off and let the caps discharge before switching output transformers each time.

First caution - you need to give each transformer at least 50-100 hours of music, fairly loud, before you can make meaningful comparisons. I did it with the local classical music station and hefty 8-ohm load resistors in place of speakers, but still it takes weeks to get them all burned in. I did some listening, shared it with a crowd at a club meeting, and we may have done a bit more, later. We had a 2A3 amp with the TFA-204 (series feed), a DS-025, some popular-at-the-time Japanese high-end output transformer, and at least one other I can't remember - might have been an FS-030? Or a Hammond 125E? Anyhow, an interesting experiment. Then I took it all apart.

It was worth doing as an educational experiment - I learned quite a bit.

Paul Joppa


Offline tsingle999

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Reply #5 on: November 02, 2012, 03:22:17 PM
Xavier so you are saying i need to add to my collection! :) seriously though i think it would be good experience to listen to all the flavors because of what you are saying.
Thanks for the input guys: i will not attempt switches. But because the sex amp iron is such a pain to put in and out i think i may just breadboard them up and use a terminal strip to make connections to listen to each piece one at a time. Im not so much concerned about switching rapidly as being able to taste each variation and live with it for awhile. Or i may just mount it without bolting it down (which is a big part of the switch headache).
As for the other iron i preferred the nickel over the cobalt and cobalt stripe in the paramount. So it went in the sr45 and it sounds so good i refuse to pull it! But i think i will. I guess i sorta wanna keep the cobalts cuz they prob wont be made again. Thought it would be cool to make a MQ chassis that displays it and has the ability to switch to it maybe with a bit of soldering...

SGS iTransporter with Qobuz & Roon to Optical Rendu to BH DAC (Battery) / Wavelegth Cosecant to BeePre to 300b(ehemoths) to Jagers.
Bottlehead Stat headphone amp with Wavelength Brick DAC


Offline 2wo

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Reply #6 on: November 03, 2012, 06:49:51 PM
Wow, I have nickel in my SR-45 now. Can't imagine cobalt...John

John S.


Offline tsingle999

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Reply #7 on: November 03, 2012, 11:24:27 PM
Ya i gotta try it in there!
Hey what about a connector for the sex amp iron like a car stereo connectors? So i can cold swap the iron easily right on the sex amp. Turn the bolt upside down so it would be easy to swap pieces. Try different ones on each channel?

SGS iTransporter with Qobuz & Roon to Optical Rendu to BH DAC (Battery) / Wavelegth Cosecant to BeePre to 300b(ehemoths) to Jagers.
Bottlehead Stat headphone amp with Wavelength Brick DAC


Offline 2wo

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Reply #8 on: November 04, 2012, 04:24:02 AM
That would work. What I did was to wire binding post to the output of  each transformer and a pair of leads to the primary. Then I rigged binding post under the amp for the primary. I put each transformer in a little plastic Tupperware container and just sat them next to the amp...John     

John S.


Offline tsingle999

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Reply #9 on: November 12, 2012, 06:04:08 PM
The old tranny tupperware trick! I like it!
Actually swapping the iron wasn't so bad in terms of soldering the leads. I put in new bolts upside down so that i can more easily just slide the outputs off after desoldering. Im going to give the m4 a go. Start the breakin tomorrow...

SGS iTransporter with Qobuz & Roon to Optical Rendu to BH DAC (Battery) / Wavelegth Cosecant to BeePre to 300b(ehemoths) to Jagers.
Bottlehead Stat headphone amp with Wavelength Brick DAC


Offline tsingle999

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Reply #10 on: November 18, 2012, 07:44:32 AM
Ok I've been comparing the cobalt to the nickel in the jr format (both well broken in)  in my sr-45. One tranny in each amp. Wow very different. The cobalt has much more high frequency resolution more air and spaciousness. it Has a sharper, crisper almost harder edge to it. The nickel is more warm and seems to give better mid and bass resolution. Actually the bass seems deeper and more pronounced with the nickels. Its like the tone of the kick drum is heard compared to the cobalts or anything else. This quality of the bass is why i have preferred the sr-45 over the other amps i have tried. The nickel is definitely a more delicate sound. Its scary the voices are so completely different in each speaker. I think i prefer the nickel but its very close and the more i listen the more i appreciate the sound of the cobalt. I guess its like appreciating wine or chocolate...

SGS iTransporter with Qobuz & Roon to Optical Rendu to BH DAC (Battery) / Wavelegth Cosecant to BeePre to 300b(ehemoths) to Jagers.
Bottlehead Stat headphone amp with Wavelength Brick DAC


Offline tsingle999

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Reply #11 on: November 18, 2012, 08:16:27 AM
So im comparing m4 with a cobalt pinstripe to cobalt. Bass is more similar to nickel with the m4c. But on 1 track i use there is background drums that sound so cool with nickel and they came out great with m4c but they were nonexistent with cobalts. I remember hearing that track with nickel for the first time and being amazed that there was this hidden drum track that other amps can't resolve. Puts a bit of a damper on the cobalts...i think i need a cobalt tranny with a nickel pinstripe:)

SGS iTransporter with Qobuz & Roon to Optical Rendu to BH DAC (Battery) / Wavelegth Cosecant to BeePre to 300b(ehemoths) to Jagers.
Bottlehead Stat headphone amp with Wavelength Brick DAC


Offline tsingle999

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Reply #12 on: November 18, 2012, 08:56:16 AM
Oh the hazards of comparing single outputs... After putting the nickel in for the cobalts i realized that drum track was only on the left channel:)

SGS iTransporter with Qobuz & Roon to Optical Rendu to BH DAC (Battery) / Wavelegth Cosecant to BeePre to 300b(ehemoths) to Jagers.
Bottlehead Stat headphone amp with Wavelength Brick DAC


Offline tsingle999

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Reply #13 on: November 18, 2012, 09:02:53 AM
The m4 cobalt pin stripe is closer to nickel in the bass. May be the best of both worlds...
Oh what to do?

SGS iTransporter with Qobuz & Roon to Optical Rendu to BH DAC (Battery) / Wavelegth Cosecant to BeePre to 300b(ehemoths) to Jagers.
Bottlehead Stat headphone amp with Wavelength Brick DAC


Offline johnsonad

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Reply #14 on: November 18, 2012, 10:18:23 AM
Sell me the cobalt trannies. You will feel better for it :)

Aaron Johnson