[Michgelsen]

I do not have experience with many different amps, but remember when I upgraded from my SRM-T1 to a SRM-717 that I actually found the T1 somewhat better with the SR-202.
To my ears, the SR-202 are quite neutral: no part of the frequency spectrum stands out and the amount of bass and highs are perfect for my taste. There's certainly no etch or any other annoying emphasis, which was a relief compared to the Lambda Signature (etch) and HE60 (too bright at times) I had at the time. Therefore I understand why they have such a good reputation. They remain a refreshing change from my SR-007 from time to time. Even though they're not as detailed or nuanced as the SR-007, I value their airy, spacious sound and more extended highs.
 
 
Quote:

Huh, disagreement. So maybe there's not much to be gained from an amp upgrade? And spritzer says the 202s are one of the best lambdas, up there with 404LE and Lambda Sigs. Anyone else care to weigh in?

 

[milosz]

Quote:

 
Is it easy to build?

 
I would say that there are a number of challenges.  If you've built solid state DIY before, you may be so used to low voltage solid state that you make mistakes with the high-voltage solid state parts in the DIY T2.  You need special TO-220 insulators, for example, regular mica rectangles or silicone pads will not work, the high voltage will just arc through.  Also some of the parts are hard to obtain, being out of production for a long period of time.  Then too there are COUNTERFEITS of some of these parts being sold, which don't work and worse, which will cause the amplifier to blow up and take $500~$1,000 of hard-to-obtain parts with them. So you'd be wise to run tests on ALL the transistors used in the build to make sure they meet spec.
 
Also a challenge is the size of the two chassis that must be built. There's no off-the-shelf metal chassis casework that will fit these things, you have to fabricate them or have them special made.  (Two chassis- one for the amp, one for the power supply.)  The main amp circuit board is 16 inches deep by 12 inches wide... an odd, large size.  Heat sinks flank it.
 
Another complication is the difficulty of testing the finished item- you can't just hook your oscilloscope up to the output, the voltage is too high, it'll just arc to ground in the probe or in the 'scope and there goes $500 or more in hard-to-obtain parts.  You really need to use an active high voltage differential probe, which cost about $500 (or more) used on eBay.
 
The printed circuit boards are hard to obtain- there is no source for them, unless you can get enough people together to have a batch screened off. (The designs for the boards can be got.)  You could also make them yourself, but they are large and the facilities you'd need would be substantial.
 
Last but not least is the complexity- there are a lot of parts, and that means a lot of chances to put the wrong resistor in someplace, or a diode in backwards... and then there goes $500 (or more) worth of transistors when you plug the thing in.  With something like a balanced, dual power supply Beta 22 there are probably MORE parts- but if a diode is in wrong or something you're only likely to lose a pair of easily-obtained MOSFETs worth $30.
 
But it CAN be done.  There are perhaps 15 (?) people who have successfully built them.

 

[kevin gilmore]

17 of my 20 chassis run are complete and running.
at least 3 more were built with a different chassis and
are also working. If you get real parts and pay attention
it usually works right the first time.

 

[livewire]

Quote:

Huh, disagreement. So maybe there's not much to be gained from an amp upgrade? And spritzer says the 202s are one of the best lambdas, up there with 404LE and Lambda Sigs. Anyone else care to weigh in?

Sure.
I really like the 202s driven by the little 252 amp. Just my 2 cents.
I've tried the 202s with my KGSSHV, at a SPL of 100dB, they begin to distort.
I'm in a happy place running them at <95 dB on the 252 amp. Clear as a bell.
 
The KGSSHV really shines with the harder to drive O2s. It also does well with my Koss ESP-950s.
And yes, 100 dB will kill your hearing quick.
I'm sure the headbangers will disagree. "Bang your head, metal health will drive you mad!"

 

[Tilpo]

Sure.
I really like the 202s driven by the little 252 amp. Just my 2 cents.
I've tried the 202s with my KGSSHV, at a SPL of 100dB, they begin to distort.
I'm in a happy place running them at <95 dB on the 252 amp. Clear as a bell.

The KGSSHV really shines with the harder to drive O2s. It also does well with my Koss ESP-950s.
And yes, 100 dB will kill your hearing quick.
I'm sure the headbangers will disagree. "Bang your head, metal health will drive you mad!"

I would headbang with expensive electrostats on my head. No sir, I prefer leaning back in my rather comfortable chair instead.

 

[Amarphael]

Ha, the SR-007 is the ultimate headbanger's cans didn't you know? You can even bend the metal arcs to squeeze even moar hardcore-ness out of them... 

The SR-202, NOT. it's more head-bobbing styled.

 

[Headdie]

SR-X/Mk3 question:
 
I'd like to fit the Mk3 drivers into a new headphone frame for better comfort. I have a 20 year old pair of DT-990 that could do the job I guess. However, I'm reluctant to scrap them in the operation. A cheap pair of ??? from eBay would be better. A comfy open circumaural one of course... Any idea out there ?
 
Regards,

 

[Tilpo]

Ha, the SR-007 is the ultimate headbanger's cans didn't you know? You can even bend the metal arcs to squeeze even moar hardcore-ness out of them...  The SR-202, NOT. it's more head-bobbing styled.

I tried slight headbanging movements with it just now. It moves back and forth quite a bit. And... it creaks really loudly, but that's not something you'd notice at high listening levels.

 

[anetode]

So, is there any difference in stat amps for us lowly suckers who listen to an avg db in the 70s? I'm amazed at the bass that an 02Mk1 can pull off when blasted, but that's a 1 in a 1000 occurrence.

 

[jjinh]

Quote:

And spritzer says the 202s are one of the best lambdas, up there with 404LE and Lambda Sigs. Anyone else care to weigh in?
 
Quote:

I really like the 202s driven by the little 252 amp. Just my 2 cents.

 

 
I have more than one pair of SR-202s so I suppose I'm also a fan of them... but then again I may be wrong as I like the Lambda Pros (and Lambda Sigs) more than the 404LE.

 

[padam]

Quote:

SR-X/Mk3 question:
 
I'd like to fit the Mk3 drivers into a new headphone frame for better comfort. I have a 20 year old pair of DT-990 that could do the job I guess. However, I'm reluctant to scrap them in the operation. A cheap pair of ??? from eBay would be better. A comfy open circumaural one of course... Any idea out there ?
 
Regards,

Unfortunately I have no idea about the exact models but my friend say that Telefunken, Mainz, Audio-Technica headbands should fit from that era (he is using the latter but doesn't know which one exactly.
 
I managed to fit it fairly well with the stock headband and new pleather pads but I might look for an alternative headband myself, I will let you know if I found one.

 

[Magick Man]

So I ran into a good deal on some 4070s and bought them, it was a spur of the moment/impulse thing. Who has heard them and what do you think?


(My previous question probably got lost in the shuffle, serves me right for putting it at the end of an unrelated post...)

 

[NamelessPFG]

To chime in on the SR-202 discussion, they were good, but not SR-Lambda good, even if my set has rebuilt drivers with thicker (2.5um compared to stock 2um) diaphragms and is obviously not representative of a stock SR-Lambda. There was a bit of harsh grain to the sound by comparison, and vocals also sounded a bit recessed.
 
Then again, I couldn't use the same amp setups for both due to the Normal/Pro bias difference. The SR-202 was fed by an SRM-212, while I had the SR-Lambda driven by an Onkyo TX-SV515PRO and a SRD-7/SB. It's a difference I wish wasn't there for the sake of isolating variables and all that, but I just didn't have an amp with both Normal and Pro bias jacks.
 
Sound quality aside, there's the headband/arc design. Simply put, I prefer the original, pre-Nova series headband. The headband sliders don't slip upwards nearly as often when putting the headphones on, the clamping force is lower (feels like they're just resting on your head instead of actually squeezing on), and it doesn't sound nearly as squeaky, either.
 
That's why I sold off my SR-202 instead. I guess newer isn't always better when it comes to Stax, and for now, I'll just stick to the Normal bias SR-Lambda, even though they're obviously harder to get due to being a discontinued vintage product.
 
Would I take the SR-202 over every other non-SR-Lambda headphone I've tried, though? Most certainly; it still has many of the desirable Lambda-series characteristics in its presentation, and you could do far worse for headphones in its price range.

 

[milosz]

Quote:

17 of my 20 chassis run are complete and running.
at least 3 more were built with a different chassis and
are also working. If you get real parts and pay attention
it usually works right the first time.

 
OK  so there are 20 up and running currently.  That's pretty impressive.  I wonder, has any owner built one then found he needed to sell it later?  You know, granny required emergency gluteal liposuction or something and funds were needed...
 
I think you underestimate the challenge a little, Kevin.  For a patient, experienced builder who takes the time to read through the threads to see where others found pitfalls and solutions, it is something that CAN be done, certainly.  And while there are many here who fit the description of 'experienced builder' there are many more readers here are either first-time builders or folks who built a CMOY type thing, or a couple of other small projects, and while such folks needn't be warned totally AWAY from the project, I think anyone with low or medium levels of electronic construction experience needs to really be prepared for the challenges he will face building this amplifier.  

 

[Tilpo]

OK  so there are 20 up and running currently.  That's pretty impressive.  I wonder, has any owner built one then found he needed to sell it later?  You know, granny required emergency gluteal liposuction or something and funds were needed...

I think you underestimate the challenge a little, Kevin.  For a patient, experienced builder who takes the time to read through the threads to see where others found pitfalls and solutions, it is something that CAN be done, certainly.  And while there are many here who fit the description of 'experienced builder' there are many more readers here are either first-time builders or folks who built a CMOY type thing, or a couple of other small projects, and while such folks needn't be warned totally AWAY from the project, I think anyone with low or medium levels of electronic construction experience needs to really be prepared for the challenges he will face building this amplifier.  

As an inexperienced builder building the Beta22 was already too difficult for me with hindsight. I rushed the soldering job and underestimated the difficulty in properly wiring it without proper experience. As a result I'm still chasing the mistakes I made back in November/December, and I'm not even sure I'll be finishing it in the coming month.

That's bad enough with a Beta22, but imagine the same thing happening with a stat amp. It would be an incredible source of frustration and burn an incredible amount of money and time.

And besides, how much better is the T2 anyway than other stat builds? I imagine there should be easier projects with less hard to source parts, even though I guess any stat build will still require quite a bit more experience than a simple headphone amplifier.