Good News... the Mucho Mas Macho XA252 has been putting some awesome music.... new super ventilated Mk II version with bigger device heat sinks and a color changing power supply (*)
Here's a snapshot.... I will post heat measurements as I go along...
As it now stands, it looks like the heatsinks are settled at around 48C.
BTW,
Oh, BTW, surely those fools over at ASR have nothing on me.... at least I listen.
It sounds... awesome so far. I need to get a handle on it before I slip the.... he... he..... P3 I got for "evaluation" with swapping op amps.... I already got the Burson v5 and v6 Vivids ( the Classics are out of stock everywhere and I'm not gonna rip into the DAC to get my only set )...
Life is sweet.
(*) Yeah, a design surely meant to drive my technical retentiveness sky high... does it sound better with green, red or blue? Does the DAC sound better when the LEDs are off?
Here's a snapshot.... I will post heat measurements as I go along...
As it now stands, it looks like the heatsinks are settled at around 48C.
BTW,
Oh, BTW, surely those fools over at ASR have nothing on me.... at least I listen.
It sounds... awesome so far. I need to get a handle on it before I slip the.... he... he..... P3 I got for "evaluation" with swapping op amps.... I already got the Burson v5 and v6 Vivids ( the Classics are out of stock everywhere and I'm not gonna rip into the DAC to get my only set )...
Life is sweet.
(*) Yeah, a design surely meant to drive my technical retentiveness sky high... does it sound better with green, red or blue? Does the DAC sound better when the LEDs are off?
Attachments
OK, I didn't want to mix the "Lab 101" pictures with a purely subjective post.
This amp sounds really good. Mind you, the Sissy SIT is superlative and the A2s over the Maggies are a Dream Island set up. The F4... well... I am blessed. An ARC-D70-II, Nuforce STA200, CJ MF2100... and so on bring up the middle tiers, and a bunch more.
Let's just say for the last five years I've gone from A5, F5, A2, F4, ( need more speakers ), SissySIT and now MachoSIT.
Damn, what a ride!
There's still the putative F5V-III and the Vaporware BigBaddaBingSIT.
Is the Macho SIT an end point or should I first taste the SET version... or perhaps @Zen Mod will come through with the Super Duper Bad Bing Thing? (1)?
Who knows, but right now I got The Scorpions Live on Tidal HiFi.... my wife walked out from her office to listen to it.
Dang get, @Zen Mod you really came up with a nice one here... and of course, let me, for the first time, publicly acknowledge @rhthatcher for this build (he can take credit for a lot...). I think we learned something about this one amp... it needs cooling. If you're curious how much, look at the Babysitter thread.... But, you two guys, take a bow, you two deserve a long standing ovation over this baby...
... spoiler, is seems to be running a bit cooler than the A2s but perhaps it's a newer design and the BOM is still in its youth.
THIS THING SOUNDS GREAT.... (2)
(1) The way Alek is going, that will require mono blocks in 5U/500 cases with cryogenic cooling stacks. It will also sound... sublime.
(2) Knocking on wood it lasts... ;-O
This amp sounds really good. Mind you, the Sissy SIT is superlative and the A2s over the Maggies are a Dream Island set up. The F4... well... I am blessed. An ARC-D70-II, Nuforce STA200, CJ MF2100... and so on bring up the middle tiers, and a bunch more.
Let's just say for the last five years I've gone from A5, F5, A2, F4, ( need more speakers ), SissySIT and now MachoSIT.
Damn, what a ride!
There's still the putative F5V-III and the Vaporware BigBaddaBingSIT.
Is the Macho SIT an end point or should I first taste the SET version... or perhaps @Zen Mod will come through with the Super Duper Bad Bing Thing? (1)?
Who knows, but right now I got The Scorpions Live on Tidal HiFi.... my wife walked out from her office to listen to it.
Dang get, @Zen Mod you really came up with a nice one here... and of course, let me, for the first time, publicly acknowledge @rhthatcher for this build (he can take credit for a lot...). I think we learned something about this one amp... it needs cooling. If you're curious how much, look at the Babysitter thread.... But, you two guys, take a bow, you two deserve a long standing ovation over this baby...
... spoiler, is seems to be running a bit cooler than the A2s but perhaps it's a newer design and the BOM is still in its youth.
THIS THING SOUNDS GREAT.... (2)
(1) The way Alek is going, that will require mono blocks in 5U/500 cases with cryogenic cooling stacks. It will also sound... sublime.
(2) Knocking on wood it lasts... ;-O
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For future reference. I used Aavid 504222B00000G heatsinks for the internal heatsinks. I had to drill a hole for the BD1xx parts. It was good for the IRF as-is. 6.4 degC/W rating.
The color changing power supply is using the color changing LEDs leftover from an ACA redux project.
It’s great to know the amp is singing after another 2000 mile journey west. And I can see it is passing the reference grade gold standard benchmark - Bilateral Hoff Test.
The color changing power supply is using the color changing LEDs leftover from an ACA redux project.
It’s great to know the amp is singing after another 2000 mile journey west. And I can see it is passing the reference grade gold standard benchmark - Bilateral Hoff Test.
About that color changing power supply... you can imagine our consternation when we opened up the case, sniffing for smoke and the supply LEDs kept changing... I thought it was red, my daughter said it was green... blue? When the smoke got suddenly heavy, we shut her down.
Initial tests, out in the open show a >5C variation from no fan to full dual fan at high speed. That's very little fluctuation. As I need to learn this fellow fast, I will wait before I risk putting it in one of the lower shelves.
Again, more on those measurements will post in the babysitter thread.
Over the AN K/LX speakers, with Tidal HiFi over Burson Play with v6 Classic opamps it sounds extremely natural and relaxed. Very low noise level ( the preamp is a CJ ET3SE.. see the picture above ) and extended highs. I'd say the sound is very engaging... like the SissySIT but with more cojones. A bit more dynamic. Those are my initial impressions... wait 'till I play Can Can... just hope it doesn't turn again into Can {smoke.....]
Nowadays, Hoff always monitors burn in of new solid state amps....
Initial tests, out in the open show a >5C variation from no fan to full dual fan at high speed. That's very little fluctuation. As I need to learn this fellow fast, I will wait before I risk putting it in one of the lower shelves.
Again, more on those measurements will post in the babysitter thread.
Over the AN K/LX speakers, with Tidal HiFi over Burson Play with v6 Classic opamps it sounds extremely natural and relaxed. Very low noise level ( the preamp is a CJ ET3SE.. see the picture above ) and extended highs. I'd say the sound is very engaging... like the SissySIT but with more cojones. A bit more dynamic. Those are my initial impressions... wait 'till I play Can Can... just hope it doesn't turn again into Can {smoke.....]
Nowadays, Hoff always monitors burn in of new solid state amps....
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Don't ask me... but the UPS people probably think I'm nuts getting these packages....
I think it says something like new cooler internal parts cooler than the Hoff!!!.... don't ask me, ask @rhthatcher
But, yeah, having the extremely cool (sort of in a german-american way) Hoff looking down at amps in tests keeps them cooler... dude!
I think it says something like new cooler internal parts cooler than the Hoff!!!.... don't ask me, ask @rhthatcher
But, yeah, having the extremely cool (sort of in a german-american way) Hoff looking down at amps in tests keeps them cooler... dude!
Attachments
in my book, 0.1mA is proper matching bracket
now, LTP Iq is set to 0V65/120R=5.4mA per side, each side having place for 2SK170 ......... so even measly GR is acceptable, even without considering Papa's musings in attached article
though, ZM Omniopinionated ... I prefer having 2+2 2SK2145BL there , to having TO92 parts
why - dunno - it's more fun matching and soldering little buggers ......... and I'm happy camper whenever I think how cheap tehy are , comparing to Made of Preputium parts category
now, LTP Iq is set to 0V65/120R=5.4mA per side, each side having place for 2SK170 ......... so even measly GR is acceptable, even without considering Papa's musings in attached article
though, ZM Omniopinionated ... I prefer having 2+2 2SK2145BL there , to having TO92 parts
why - dunno - it's more fun matching and soldering little buggers ......... and I'm happy camper whenever I think how cheap tehy are , comparing to Made of Preputium parts category
Can you tell me where that case came from? Or at least the heatsink dimensions? 250mm high x 400mm long? All the cases I find with big heat sinks seem to have smaller internal dimensions. The original XA 25 appears to have 150mm x 400mm heat sinks.
^
The case is from @Gianluca, it's the deluxe case... aluminum, 5Ux400. On the 2nd round, I had him make me custom top/bottom plates with full slots on the whole thing... lots of ventilation. I honestly think the covers he built for me should be the standard version.
BTW, it turns out the issue with my Macho SIT was not overheating... once repaired, it came home, I added lots of thermometers on it.... and for four days I let it rip with the radio on..... took measurements.... temps below 50C... then I put it on the shelf... temps still below 50C.
I then put some real music and within two hours it... SMOKED again.
Anyhow.... some PM between some people.... something about a protection circuit... something about my overdriving it ( even though it was not playing louder than the SissySIT )... but at least we're getting somewhere. Hopefully now we know the issue is not with heat and this time I took more listening notes of the behavior... I guess there's some info about building it that somehow is not clear...
We'll figure it out.
Maybe someone will come up with a build guide...
To live with a prototype.... but, it does sound very good.
The case is from @Gianluca, it's the deluxe case... aluminum, 5Ux400. On the 2nd round, I had him make me custom top/bottom plates with full slots on the whole thing... lots of ventilation. I honestly think the covers he built for me should be the standard version.
BTW, it turns out the issue with my Macho SIT was not overheating... once repaired, it came home, I added lots of thermometers on it.... and for four days I let it rip with the radio on..... took measurements.... temps below 50C... then I put it on the shelf... temps still below 50C.
I then put some real music and within two hours it... SMOKED again.
Anyhow.... some PM between some people.... something about a protection circuit... something about my overdriving it ( even though it was not playing louder than the SissySIT )... but at least we're getting somewhere. Hopefully now we know the issue is not with heat and this time I took more listening notes of the behavior... I guess there's some info about building it that somehow is not clear...
We'll figure it out.
Maybe someone will come up with a build guide...
To live with a prototype.... but, it does sound very good.
My numbers for the A2 and Macho252SIT show that the A2 runs hotter... A babysitter on top of the amp, with fully ventilated top/bottom plates drops the temps about 5C. The amp temps track the room temp quite well...
I don't either need a babysitter unless your room is sitting at 30C... in which case I think you ought to turn off theamps heaters and drink some cold beer.
I need to post numbers in the babysitter thread.
I don't either need a babysitter unless your room is sitting at 30C... in which case I think you ought to turn off the
I need to post numbers in the babysitter thread.
Regarding the price of SITs, I always think about the price of Directly Heated Triode tubes. SITs are still cheaper, last longer, less and hassle and cheaper to implement (no expensive output transformers). So, even at today's prices, they compare well to tubes.
For a cheap thrill, I've found that the Lovoltech power JFETs are great!
For a cheap thrill, I've found that the Lovoltech power JFETs are great!