The diyAudio First Watt M2x

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#4,541
In support of M2x

pfarrell said:
Don, is this with Salas's UFSP? What cart? I will be trying out the Cedarburg's ASAP. Not to derail this—you can PM me too—I have found that the cart and phono pre are HUGE factors in all of this—in my system anyway—in that order. (part of why my plan is to build a deck w two arms) Ie: I can "improve" to my ears daughter card X with a cart change (and vice versa) they all seem to have root personalities though—so exciting, and that just adds to all the mystery and general awesomeness options. Plus any cap change in the C3 position of UFSP has major influences, as does loading and treble trim. Even with all of the above—one can still pick apart the same album pressed by different places from different sources...Love or not love—Michael Fremer has hours of youtube vids regarding pressings and history and opinions. Fascinating stuff.
Click to expand...

UFSP with Clarity Cap CMR in C3, DCG3 with DCSTB and TKD attenuator (not happy with TKD), have muses unstuffed. All parts stock thru Tea, All Antek trafos at design voltage. MJ's switches and SLB PSU's. Everything Quasimodo that will take it. AT 33PTG-2 cart. Unrecapped SP-10 with obsidian plinth. Short list for new changes, UBiB for DCG3, Muses for same, Hana Cart, OSMC and probably some IPS6 and 7 reviews as cards are built. I have an intermediate list that includes TT stuff, continuing box cleanup and trying to build a library of great pressings. All designed to get the most out of the M2x. Must keep the music playing along the journey. Took me too long to get the first notes out.😀

Treble trim?

Always open to great ideas😉

Thanks for pressing tip.

R,
Don
 
#4,543
donhughes111 said:
UFSP with Clarity Cap CMR in C3, DCG3 with DCSTB and TKD attenuator (not happy with TKD), have muses unstuffed. All parts stock thru Tea, All Antek trafos at design voltage. MJ's switches and SLB PSU's. Everything Quasimodo that will take it. AT 33PTG-2 cart. Unrecapped SP-10 with obsidian plinth. Short list for new changes, UBiB for DCG3, Muses for same, Hana Cart, OSMC and probably some IPS6 and 7 reviews as cards are built. I have an intermediate list that includes TT stuff, continuing box cleanup and trying to build a library of great pressings. All designed to get the most out of the M2x. Must keep the music playing along the journey. Took me too long to get the first notes out.😀

Treble trim?

Always open to great ideas😉

Thanks for pressing tip.

R,
Don
Click to expand...

Can you give me the decryption key so I can understand the post?
Maybe in morphs into a picture of...a sexy amp? 😀😀😀
 
#4,545
Hi folks, made a mistake in populating the boards, put a 47R instead of 47K in R6 and R7. Ugh... Saw 15V on outputs and some smoke and killed power right away, but I am guessing I need to replace the output FETs. Fortunately only fired up one channel, but anything else that should be changed? Thanks!
 
#4,547
Please evaluate the sound of new M2x circuitry

I'm seeking volunteers to help me perform listening auditions / evaluations of new M2x daughter card configurations.

The listening tests will use the IPS7 circuit board, plus a cadre of unusual opamps that are seldom/never deployed in M2x's ... because they're surface mount parts (SOIC-8). However, I've soldered the opamp chips on SOIC-to-DIP adapters for these experiments, so they function as DIP-8s and thus are 100% compatible with IPS7 boards.

None of the opamps used in these tests are unknown or mysterious; every one of them is available worldwide, and their excellent datasheet specifications are published globally. Despite this, nobody has tried ANY of them in an M2x amplifier as far as I can tell, either with a Tucson or an IPS7 or anything else. I searched this thread for each of the part numbers and came up empty, every time.

So, I'd like to get the evaluations and critiques and opinions and listening evaluations of other M2x owners, and find out if one or more of these chips give terrific sound for YOU. As the designer and experiment-creator, I might fall victim to "Proud Parent bias", but YOU probably don't. So your opinions and evaluations are probably less biased (more objective) than mine.

IF YOU'RE INTERESTED

Please PM me if, and only if, you can truthfully promise that you'll evaluate two different opamp types, in your IPS7 boards, in your M2x, within four weeks of receiving the chips. And then write up your impressions and evaluation results as a post in this thread. (Slowpokes are undoubtedly wonderful human beings, but they're not my first choice for this experiment.)

Hopefully you'll discover a hidden gem, and your findings will help steer other M2x owners toward a new avenue for great sound using the IPS7 board. Then everybody will benefit from your experiences.

I'm not going to say anything specific about the chips which are (or are not!) part of the experiment. I don't want to prejudice the listeners or to pre-bias their opinions.

Naturally the opamps and adapters will be yours to keep after the evaluation is complete.

Thanks for reading this!
 
#4,548
Sadly, I suck at listening impressions, unless the differences are large. Besides, if I have that kind of time in the next few weeks, I will be doing an IPS6 build. The rest of my parts came in today.


Your SOIC opamps sound cool though, I look forward to the reviews. I would, of course have to compare them to Cedarburg. (Heh, it is the last board I built!)
 
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#4,549
i have listening the M2x for month and was not impress at all about his sound,
so i put it in my garage and return to my beloved tube SET , my moded alpeh 3 was better too ..

than last week i just realise that i had the two input transfomer mounted in the wrong side 😱 Damn !

i feel sorry for Mr Pass and Mark spending their precious time to elaborate fine Diy products just to be ruined by a french fart 😀

I'm seeking volunteers to help me perform listening auditions / evaluations of new M2x daughter card configurations.
Click to expand...

so i'm sorry but will Not be volunteerfor the evaluation of the new daughter.. 🙂
 
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#4,550
Hello out there,



I am testing some JRC Opamps on my IPS7 at the moment....


I am curious what Mark was digging out of the 'jungle' of SOIC8-Opamps? 🙄


And I am waiting for delivery of the last few parts for 'Cedarburg'.


So many boards and so many Opamps....😀


Have fun!
Greets
Dirk
 
#4,551
Some more SOIC-8 to DIP-8 adapters necessary....? 😀


Heat up your hot irons...


Dirk
 

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#4,552
Please evaluate the sound of new M2x circuitry

I'm seeking volunteers to help me perform listening auditions / evaluations of new M2x daughter card configurations.

The listening tests will use the IPS7 circuit board, plus a cadre of unusual opamps that are seldom/never deployed in M2x's ... because they're surface mount parts (SOIC-8). However, I've soldered the opamp chips on SOIC-to-DIP adapters for these experiments, so they function as DIP-8s and thus are 100% compatible with IPS7 boards.

None of the opamps used in these tests are unknown or mysterious; every one of them is available worldwide, and their excellent datasheet specifications are published globally. Despite this, nobody has tried ANY of them in an M2x amplifier as far as I can tell, either with a Tucson or an IPS7 or anything else. I searched this thread for each of the part numbers and came up empty, every time.

So, I'd like to get the evaluations and critiques and opinions and listening evaluations of other M2x owners, and find out if one or more of these chips give terrific sound for YOU. As the designer and experiment-creator, I might fall victim to "Proud Parent bias", but YOU probably don't. So your opinions and evaluations are probably less biased (more objective) than mine.

IF YOU'RE INTERESTED

Please PM me if, and only if, you can truthfully promise that you'll evaluate two different opamp types, in your IPS7 boards, in your M2x, within four weeks of receiving the chips. And then write up your impressions and evaluation results as a post in this thread. (Slowpokes are undoubtedly wonderful human beings, but they're not my first choice for this experiment.)

Hopefully you'll discover a hidden gem, and your findings will help steer other M2x owners toward a new avenue for great sound using the IPS7 board. Then everybody will benefit from your experiences.

I'm not going to say anything specific about the chips which are (or are not!) part of the experiment. I don't want to prejudice the listeners or to pre-bias their opinions.

Naturally the opamps and adapters will be yours to keep after the evaluation is complete.

Thanks for reading this!
 
#4,553
Mark must have created a major global parts shortage with the release of the Cedarburg. I had to shop around to find parts. I checked Octopart but couldn't find one transistor, D45H11G, in stock in the US from a company that didn't sell in large lots. Other companies ship them from abroad and estimated times are measured in months.

I thought I had D45H11G in stock but there was only one left in the bag. Drat! Can anybody sell me 3 of them if I pay for the transistors and shipping?

Thanks
 
#4,555
Switched on my M2X today and it didn't get warm, opened it up to find the left channel -ve out from the psu a bit burnt and R14 on LH amp slightly brown. I measured Q2 with my DMM and D and G read OL both ways on diode range, G wrt D on ohms is 46.5 k ohms and 47.4K the other way. Any idea what could be wrong and any other checks to carry out?
 
#4,560
Beautiful work, banderson546! Congratulations. Looks like you've got a "mixed marriage" of power transistors. The one at top left has chamfered corners on the mounting tab, while the one at bottom right has square corners. Maybe one is STMicroelectronics and the other is ONSemiconductor? It's nothing to worry about, that'll work fine.
 
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