Elephas Posted June 19, 2009 Report Posted June 19, 2009 Please dispose of those two, large round canisters properly by sending them to me. Thanks! As yourpasswordsucks points out, it does seem a bit cramped in there. Removing those two large round things would make things nice and roomy. We need moar pics!!!!!! *stunned* *shakes head, disoriented* Whoa, dude, your plus 12 Thunder God Shout ability is making me deaf. Full res too!!!! *partially deaf* *feels like I have Etymotic ER20's in my ears* I'm afraid. My tired old camera only goes up to a puny 5 megapixels. People will make fun.
Elephas Posted June 19, 2009 Report Posted June 19, 2009 (click thumbnails to view 2560 x 1920 images) Amp section Power supply
spritzer Posted June 19, 2009 Report Posted June 19, 2009 Thanks for the pics. It is certainly better made then some of the other clusterfucks, it even has heatshrink over exposed wire and the soldering isn't all utterly terrible. I don't know what's up with the coupling caps since they appear to be serial connected 0.01uF units which are way too small for this amp. The V+ for the last stage looks to be uninsulated (the left side of the large resistors towards the back of the amp) which is just asking for trouble. There is only a single filament supply (which drives the LED indicator as well) which means the amp will not be easy on the output tubes. If will be a pain to strip the chassis if mine is like that... I'm afraid. My tired old camera only goes up to a puny 5 megapixels. People will make fun. I have the same problem.
Elephas Posted June 19, 2009 Report Posted June 19, 2009 I don't know much about DIY electronics, so I would appreciate any comments about the design, parts, potential safety issues, etc. of the ES-1. It sounds very good to me, the best I've ever heard from the O2Mk1 and O2Mk2. With the HE90, I can't decide between the ES-1 and the Aristaeus, they each do some things better than the other.
blubliss Posted June 19, 2009 Report Posted June 19, 2009 You may send me the Aristaeus to help you decide, it's all right .
spritzer Posted June 19, 2009 Report Posted June 19, 2009 I don't know much about DIY electronics, so I would appreciate any comments about the design, parts, potential safety issues, etc. of the ES-1. It sounds very good to me, the best I've ever heard from the O2Mk1 and O2Mk2. With the HE90, I can't decide between the ES-1 and the Aristaeus, they each do some things better than the other. You'll have a PM shortly. You may send me the Aristaeus to help you decide, it's all right . What a great offer!!
Asr Posted June 23, 2009 Report Posted June 23, 2009 Ok another question: SR-404 or 4070? And if the SR-404, Signature or Limited? I've decided I'm going to pass up the SR-Omega/SRM-T1W deal in favor of something cheaper. I'm primarily looking for a sonic alternative to OII MKI and SR-X MKIII. It'd be nice to get something about as "bright" as the SR-X MKIII but with a different spin, if possible.
HeadphoneAddict Posted June 24, 2009 Report Posted June 24, 2009 Ok another question: SR-404 or 4070? And if the SR-404, Signature or Limited? I've decided I'm going to pass up the SR-Omega/SRM-T1W deal in favor of something cheaper. I'm primarily looking for a sonic alternative to OII MKI and SR-X MKIII. It'd be nice to get something about as "bright" as the SR-X MKIII but with a different spin, if possible. Try an SR5-NB (gold edition).
padam Posted June 24, 2009 Report Posted June 24, 2009 According to the few impressions that I found, the 404 Limited probably doesn't worth that much extra money over the 404 (or even the 303) but you may be able to get it cheaper at Yahoo Japan. By the way, there is two there at the moment, if somebody is interested. The old Lambda Signature could also be very interesting and also the Sennheiser HE60 is said to be on the bright side as well. Although it is still very expensive and if something goes wrong with it, it may cost a fortune to repair which is makes it even less appealing than it already is (even so, this is still something I would really like to hear).
Smeggy Posted June 25, 2009 Report Posted June 25, 2009 Question for the 'stat techies, any idea what kind of load a stax transfo box presents to an amp? The Beta 22 needs the zobel network for speakers inductive loads, but do transfo boxes present this type of load as well? Basically I'm asking if it's safe to run the transfo boxes (stax, Koss, sony) without a zobel and avoid instability. I'm already doing so by plugging the box into the headphone socket and it works and sounds great but will stop if it's potentially harmful and get the bits for the zobel. BTW, the Beyer ET sounds damn nice from it!
luvdunhill Posted June 25, 2009 Report Posted June 25, 2009 Question for the 'stat techies, any idea what kind of load a stax transfo box presents to an amp? The Beta 22 needs the zobel network for speakers inductive loads, but do transfo boxes present this type of load as well? Basically I'm asking if it's safe to run the transfo boxes (stax, Koss, sony) without a zobel and avoid instability. I'm already doing so by plugging the box into the headphone socket and it works and sounds great but will stop if it's potentially harmful and get the bits for the zobel. BTW, the Beyer ET sounds damn nice from it! I my opinion, any amp used as a speaker amp should have output protection, preferably something active. However, if you want to go passive, a simple capacitor / resistor zobel in my opinion is inadequate for what you're doing and an inductor (RLC) like amb recommends for the beta24 would be a safer option. Since a beta22 doesn't have any output short protection, maybe an active speaker protection device is a better choice.
Torpedo Posted June 25, 2009 Report Posted June 25, 2009 I looked at the input circuit of the SRD7 and when switched on to drive the Stax phones, it presents an 8 Ohm impedance to the speakers outs of the amp. It has 2x16 Ohms resistors in parallel for channel. When switched to "speakers" the circuit just drives the signal to the box own speaker outs. So I think it's as a suitable load for the B22 as a pair of speakers as long as the B22 is made to drive them. The trafo box for their electrets (I have two of them) also have those resistors. FWIW my B22 has been driving a SRD7>O2 for several weeks without the slightest problem. Not sure if my B22 has the zobel inside, it's Nate who should tell since he built it.
Smeggy Posted June 25, 2009 Report Posted June 25, 2009 so you think stax boxes are potentially that dangerous to the amp? Hmm. Is there anything you know of that would work as a plug in solution and not be too involved for a dummy like me. I've never heard of anyone using more than a zobel for these so I'm no even sure what I'm looking for. A quick Google search doesn't show anything that looks useful.
luvdunhill Posted June 25, 2009 Report Posted June 25, 2009 So I think it's as a suitable load for the B22 what about the inductive component of the load, after all you're driving a large transformer...
Smeggy Posted June 25, 2009 Report Posted June 25, 2009 I looked at the input circuit of the SRD7 and when switched on to drive the Stax phones, it presents an 8 Ohm impedance to the speakers outs of the amp. It has 2x16 Ohms resistors in parallel for channel. When switched to "speakers" the circuit just drives the signal to the box own speaker outs. So I think it's as a suitable load for the B22 as a pair of speakers as long as the B22 is made to drive them. The trafo box for their electrets (I have two of them) also have those resistors. FWIW my B22 has been driving a SRD7>O2 for several weeks without the slightest problem. Not sure if my B22 has the zobel inside, it's Nate who should tell since he built it. As a temp measure I've just soldered a 1/4" jack to my srd-7 and am running it from the headphone socket as the full 18wpc goes there anyway so it's getting the signal right off the boards.
Torpedo Posted June 25, 2009 Report Posted June 25, 2009 what about the inductive component of the load, after all you're driving a large transformer... Not that large hehehe. I can't say how the B22 "feels" electrically driving the SRD7 (or the other trafo boxes) and the phones, and if that's any different than driving the boxes alone without phones connected. This last scenario isn't something I've tried, but driving the boxes and phones it didn't get any warmer than usual, or produce any anomalous response I've detected.
Torpedo Posted June 25, 2009 Report Posted June 25, 2009 As a temp measure I've just soldered a 1/4" jack to my srd-7 and am running it from the headphone socket as the full 18wpc goes there anyway so it's getting the signal right off the boards. That's a lower impedance than most headphones will load the phones output, but still higher than many speakers', so not sure if the zobel would be still needed. I suppose the zobel is required to have a constant impedance load on the output, to avoid the high current intensity demands from low impedance speakers. While quite powerful and "overkill" maybe the B22 "as is" won't be very happy driving 2 Ohms at 100Hz.
n_maher Posted June 25, 2009 Report Posted June 25, 2009 it's Nate who should tell since he built it. I most certainly did not build Smeggy's amp. My opinion of the driving the Stax box with a beta22, do so at your own risk. My understanding is that it requires the amp to be run quite hard and as Mark said may include a significant inductive load which even with a Zobel may cause the amp to misbehave. And when it does, well, look out.
Voltron Posted June 25, 2009 Report Posted June 25, 2009 . . . FWIW my B22 has been driving a SRD7>O2 for several weeks without the slightest problem. Not sure if my B22 has the zobel inside, it's Nate who should tell since he built it. I most certainly did not build Smeggy's amp. My opinion of the driving the Stax box with a beta22, do so at your own risk. My understanding is that it requires the amp to be run quite hard and as Mark said may include a significant inductive load which even with a Zobel may cause the amp to misbehave. And when it does, well, look out. I think Antonio was saying you built his B22 although I don't know if that is true either.
Torpedo Posted June 25, 2009 Report Posted June 25, 2009 I most certainly did not build Smeggy's amp. My opinion of the driving the Stax box with a beta22, do so at your own risk. My understanding is that it requires the amp to be run quite hard and as Mark said may include a significant inductive load which even with a Zobel may cause the amp to misbehave. And when it does, well, look out. Maybe I've been just lucky, but from the speaker outs (which I still don't know if have the zobel installed, but I suppose it has) the B22 didn't do anything strange, nor suffered any damage, driving the SRD-7/O2 combo for several weeks for more than 4 hours many days. Sound was very good, I must say. Good enough to let me recognize the O2 virtues. We also drove a friend's pair of 303 and the B22/SRD7 literally "trounced" my friend's Stax amp, which IIRC was a SRM-313.
Torpedo Posted June 25, 2009 Report Posted June 25, 2009 I think Antonio was saying you built his B22 although I don't know if that is true either. LOL well, unit's looks match the pics at AMB's site, and also has the Nugget Audio plate, but who knows, maybe Nate is outsourcing builds to China
Smeggy Posted June 25, 2009 Report Posted June 25, 2009 Yeah, the amp does drive the 'stats beautifully but I am still a little concerned. I know a couple of people drive the boxes from betas like Topedo and Kai. It seems to be fine on mine too but I really don't know enough of the technicalities to ensure I won't do damage. Maybe it's time to see if amb will chip in and advise.
Dusty Chalk Posted June 25, 2009 Report Posted June 25, 2009 I think Stax earspeakers take more speaker amp -like signals than headphone amp -like signals. I don't remember who, but I think someone has their faux srd7 set up as basically a pass-through (so basically the only thing it's doing is creating the stator voltage). That said, I don't think the Stax earspeakers present a pleasant 8 ohm or 4 ohm load, so the real boxes may actually accomodate for that. I can't imagine what else they'd be doing, other than the switching function. So as long as your amp can drive an unpleasant load, it should be fine. Someone who knows moar bettr please feel free to call me on talking out of my ass.
n_maher Posted June 25, 2009 Report Posted June 25, 2009 Pretty sure (99%) that the Zobel is on the e22 backplane board on Torpedo's amp.
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