I don't have an M2x, but if you assume that the character of the opamp remains the same between the WHAMMY and M2x...
The Muses 01 was good but a little too HiFi for my taste, I have but didn't try the 02, the 03 is excellent, I preferred it over the Burson V6 Vivid and Classic, it was only just beaten by the Staccato discrete opamp.
If you purchase the 03, be careful, the legs are made from soft copper and are easily bent.
The Muses 01 was good but a little too HiFi for my taste, I have but didn't try the 02, the 03 is excellent, I preferred it over the Burson V6 Vivid and Classic, it was only just beaten by the Staccato discrete opamp.
If you purchase the 03, be careful, the legs are made from soft copper and are easily bent.
Hello, after a long break
100hz ripple problem continued ...
I replaced the crc filter PCB with a new one. I have a total of 320mF and 0.5R resistors I have silence in the speakers with the Ischikawa card, but unfortunately Mountain View is still hum. This is how the measurement with the phone at the loudspeaker looks like.
Of course, it does not bother, but ... if others builders hear silence, I would like to do everything to have the same. I'm out of ideas. Maybe someone else has some advice?
Regards
100hz ripple problem continued ...
I replaced the crc filter PCB with a new one. I have a total of 320mF and 0.5R resistors I have silence in the speakers with the Ischikawa card, but unfortunately Mountain View is still hum. This is how the measurement with the phone at the loudspeaker looks like.
Of course, it does not bother, but ... if others builders hear silence, I would like to do everything to have the same. I'm out of ideas. Maybe someone else has some advice?
Regards
I'm left wondering if the Stacatto's would fit on my IPS7 board?
OSH-S - Single Discrete Opamp Open Sound Hybrid - Staccatoaudio
It looks like a tight fit.
Regards,
Dan
OSH-S - Single Discrete Opamp Open Sound Hybrid - Staccatoaudio
It looks like a tight fit.
Regards,
Dan
Download the IPS7 Gerbers and measure the dimensions & the part-to-part spacings. Or just send the Gerbers off to fab, get ten boards back, and measure the real thing. If brand X discrete opamp doesn't fit, the OPA134 certainly does fit. IPS7+OPA134 has won the heart of Moderator number-letter-number on this thread.
I have the IPS7's in hand and built already. I was intrigued by one poster's remarks so I went and looked at the Stacatto website. There is a certain appeal to 'boutique' parts sometimes?
Regards,
Dan
Just passing through to say thank you to everyone who made my M2x experience possible! Nelson, Mark, Jim, everyone who asked or answered questions in this thread. The M2x is the first DIY amplifier in my possession - and its a great sounding one!
My build is getting closer and closer to be a final version. I had no major problems building the main boards and power supply. But when i first mounted the boards to the heatsink i forgot to use insulation pads. Luckily i did all kinds of continuity tests before firing everything up. I corrected the mistake and switched the amp on using a bulb tester. It worked flawless, i love the bias circuit ;-)
My setup includes a modded Technics SL1200, a Salas UFSP Phono, a B1-like buffer with stepped attentuator and the M2x. My speakers are a pair of old, shabby Arcus TM65 that i rescued from trash 20 years ago. I feared that they would not be efficient enough for M2x but it seems like a they are a very good match.
I did the first listening tests using the Mountain View IPS and i was stunned about the sound. It felt like the M2x was remastering the music, i never had such a clear yet balanced sound with a wide soundstage. Bass was much better then i was expecting from a "25 Watt amp". My old amplifier was a Sony that was marketed as 2x70 Watt (RMS? Peak? i dont know). But it sounded like ****, the bass was weak and the treble sounded compressed and too loud. Maybe the Sony had problems to deal with my 4 ohm speakers.
After Mountain View i tried Ishikawa with original Toshibas. The soundstage got even bigger - wow... But the sound seemed to be a bit more "rounded" or "dull" compared to Mountain View. Voices sounded not "sharp" enough to my ear.
I wanted to keep Ishikawa but achieve a more clear sound - thats why i changed over to use Toshiba 2sk1529 and 2sj200 as output devices. I dont have the cojones to run them at 1.8 A, thats why i did not use a 0.22 ohm source resistor, instead i chose 0.33 ohm source resistors to achieve a bias current of "only" 1.66 A. I feared that the 2sk1529 would be too whimpy (everyone else uses 2sk1530 / 2sj201). But everything runs fine since weeks and weeks.. The best thing about the toshibas is that i salvaged them out of my old sony amp for free - and the N and P devices are even fairly matched! Using the Toshibas instead of the IRF240 / 9240 is a biiig improvement to the sound quality of the M2 amp. Glad i tried it
I got beautiful IPS 6 / IPS 7 pcbs from MEPER (thanks again!). IPS 7 was a breeze to assemble and gave a very neutral sound, in a positive way, using the OPA134. I used IPS 7 as a kind of "reference" to hunt down noise and hum problems. Worked out great.
But the IPS i really wanted to listen to was the IPS 6. I managed to destroy the board during setup and testing - i used the same colored wires for both power supply and DMM. After that the ZTX558 measured as resistors on my Mega328 tester.
I got new boards from Ryssen (thank you! ) and since two days i am listening to IPS 6. They are really my favourite IPS cards - maybe i am biased because it took me several months to get a pair of running IPS 6. But i think the sound is really clear and well balanced, with great bass, nice treble, very good presentation of voices and a great soundstage.
Its been a long, wild and expensive journey - but i learned a lot and i was rewarded with a great sounding amplifier. Looking forward to continue this journey with more mods and IPS cards to come...
My build is getting closer and closer to be a final version. I had no major problems building the main boards and power supply. But when i first mounted the boards to the heatsink i forgot to use insulation pads. Luckily i did all kinds of continuity tests before firing everything up. I corrected the mistake and switched the amp on using a bulb tester. It worked flawless, i love the bias circuit ;-)
My setup includes a modded Technics SL1200, a Salas UFSP Phono, a B1-like buffer with stepped attentuator and the M2x. My speakers are a pair of old, shabby Arcus TM65 that i rescued from trash 20 years ago. I feared that they would not be efficient enough for M2x but it seems like a they are a very good match.
I did the first listening tests using the Mountain View IPS and i was stunned about the sound. It felt like the M2x was remastering the music, i never had such a clear yet balanced sound with a wide soundstage. Bass was much better then i was expecting from a "25 Watt amp". My old amplifier was a Sony that was marketed as 2x70 Watt (RMS? Peak? i dont know). But it sounded like ****, the bass was weak and the treble sounded compressed and too loud. Maybe the Sony had problems to deal with my 4 ohm speakers.
After Mountain View i tried Ishikawa with original Toshibas. The soundstage got even bigger - wow... But the sound seemed to be a bit more "rounded" or "dull" compared to Mountain View. Voices sounded not "sharp" enough to my ear.
I wanted to keep Ishikawa but achieve a more clear sound - thats why i changed over to use Toshiba 2sk1529 and 2sj200 as output devices. I dont have the cojones to run them at 1.8 A, thats why i did not use a 0.22 ohm source resistor, instead i chose 0.33 ohm source resistors to achieve a bias current of "only" 1.66 A. I feared that the 2sk1529 would be too whimpy (everyone else uses 2sk1530 / 2sj201). But everything runs fine since weeks and weeks.. The best thing about the toshibas is that i salvaged them out of my old sony amp for free - and the N and P devices are even fairly matched! Using the Toshibas instead of the IRF240 / 9240 is a biiig improvement to the sound quality of the M2 amp. Glad i tried it
I got beautiful IPS 6 / IPS 7 pcbs from MEPER (thanks again!). IPS 7 was a breeze to assemble and gave a very neutral sound, in a positive way, using the OPA134. I used IPS 7 as a kind of "reference" to hunt down noise and hum problems. Worked out great.
But the IPS i really wanted to listen to was the IPS 6. I managed to destroy the board during setup and testing - i used the same colored wires for both power supply and DMM. After that the ZTX558 measured as resistors on my Mega328 tester.
I got new boards from Ryssen (thank you! ) and since two days i am listening to IPS 6. They are really my favourite IPS cards - maybe i am biased because it took me several months to get a pair of running IPS 6. But i think the sound is really clear and well balanced, with great bass, nice treble, very good presentation of voices and a great soundstage.
Its been a long, wild and expensive journey - but i learned a lot and i was rewarded with a great sounding amplifier. Looking forward to continue this journey with more mods and IPS cards to come...
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2SK1529 / 2SJ200 has a Rthjc of ~1W/°C.
Assuming you have 24V rails. 1.66A means 40°C rise between case and junction.
Assume further you have a large heatsink and that the heatsink temperature right next to the FET is 55°C.
Allow a further 5°C across the thermal insulator (e.g. Kerafol).
You will be looking at 100°C junction temperature.
Although it is not 150°C yet that causes imminent failure, it is high enough that reliability will suffer.
30W is be about the maximum I would use for the 2SK1529.
And I am speaking from experience.
Cheers,
Patrick
Assuming you have 24V rails. 1.66A means 40°C rise between case and junction.
Assume further you have a large heatsink and that the heatsink temperature right next to the FET is 55°C.
Allow a further 5°C across the thermal insulator (e.g. Kerafol).
You will be looking at 100°C junction temperature.
Although it is not 150°C yet that causes imminent failure, it is high enough that reliability will suffer.
30W is be about the maximum I would use for the 2SK1529.
And I am speaking from experience.
Cheers,
Patrick
Don, thank you. Of course i saw you I bet i learned something from one of the questions you asked here.
To me it seems like the Vishay IRF devices had "too much" soundstage and the focus got lost compared to the Toshiba 2sk1530. The reason for this may be the shelf that the IRFP9240 shows in his frequency response, see PassDiy for reference. To me it really feels that the toshibas sound more "focused" and clear then the IRFP devices.
Patrick, thank you for answer. I was wondering about that already. I asked about temperatures in the "official M2 schematic" thread but maybe i forgot to specify that i use 2sk1529. I did stare at the datasheet for a long time, especially the SOA graph and i read a lot of stuff about case temperature derating. Unfortunately did not document my way of calculation the SOA thermal derating factor. But after i draw my line it looked like that 1.66 A of bias current would be fine.. I also looked at the datasheet of the 2sk1530 for comparison but the SOA graph looked almost the same like the 2sk1529.
But your explanation seems valid to me too, i am just unable (yet) to do the calculation for myself.
I was thinking about dropping the rails to 21V by using a cap multiplier after my V3 PSU. Maybe that would help a bit.
Or would you recommend to change to 2sk1530? Would they be beefy enough to dissipate 35 - 40 watts?
I bet i learned something from one of the questions you asked here.To me it seems like the Vishay IRF devices had "too much" soundstage and the focus got lost compared to the Toshiba 2sk1530. The reason for this may be the shelf that the IRFP9240 shows in his frequency response, see PassDiy for reference. To me it really feels that the toshibas sound more "focused" and clear then the IRFP devices.
Patrick, thank you for answer. I was wondering about that already. I asked about temperatures in the "official M2 schematic" thread but maybe i forgot to specify that i use 2sk1529. I did stare at the datasheet for a long time, especially the SOA graph and i read a lot of stuff about case temperature derating. Unfortunately did not document my way of calculation the SOA thermal derating factor. But after i draw my line it looked like that 1.66 A of bias current would be fine.. I also looked at the datasheet of the 2sk1530 for comparison but the SOA graph looked almost the same like the 2sk1529.
But your explanation seems valid to me too, i am just unable (yet) to do the calculation for myself.
I was thinking about dropping the rails to 21V by using a cap multiplier after my V3 PSU. Maybe that would help a bit.
Or would you recommend to change to 2sk1530? Would they be beefy enough to dissipate 35 - 40 watts?
Another happy IPS6 builder! Hooray and congratulations.
When John Curl designed the Mark Levinson JC-2 linestage as a transconductance amplifier in 1973, he certainly was onto something good.
IPS6 is also a transconductance amplifier, but with only a single pair of matched devices, and with a CS-CE two stage topology rather than the one stage folded Lender cascode of the JC-2.
When John Curl designed the Mark Levinson JC-2 linestage as a transconductance amplifier in 1973, he certainly was onto something good.
IPS6 is also a transconductance amplifier, but with only a single pair of matched devices, and with a CS-CE two stage topology rather than the one stage folded Lender cascode of the JC-2.
Thanks Mark! I am working to learn more about electronics every day, so maybe in a few years i will read your answer again and understand what you are saying (without hours of searching and reading for every word you say)
I can only say: IPS 6 sounds great! Thumbs up!