spritzer Posted February 27, 2012 Report Share Posted February 27, 2012 Indeed. I don't understand why a SRD-7 Pro works but not a Mk2 since they are essentially identical. Quote Link to comment Share on other sites More sharing options...
grawk Posted February 27, 2012 Report Share Posted February 27, 2012 protecting yourself from lawsuit? If you're telling the truth and are providing documenting photographs, it's hard to believe there'd be grounds for a lawsuit. Quote Link to comment Share on other sites More sharing options...
Maxvla Posted February 27, 2012 Report Share Posted February 27, 2012 Unfortunately telling the truth is not good enough. Companies who have fired someone can't even tell that person's prospective new employer why he/she was fired (theft, etc) even if it's the truth and 100% provable, because it interferes with them being able to get a new job. This is the same thing as it interferes with the seller being able to conduct trade. Nice BS laws we have in this country. Quote Link to comment Share on other sites More sharing options...
morphsci Posted February 27, 2012 Report Share Posted February 27, 2012 Unfortunately telling the truth is not good enough. Companies who have fired someone can't even tell that person's prospective new employer why he/she was fired (theft, etc) even if it's the truth and 100% provable, because it interferes with them being able to get a new job. This is the same thing as it interferes with the seller being able to conduct trade. Nice BS laws we have in this country. Quote Link to comment Share on other sites More sharing options...
John Buchanan Posted February 27, 2012 Report Share Posted February 27, 2012 But they are a heavily inductive load, and that definitely pisses off some power amps. Interesting - is that why the SRD-7 Spritzer (and pre-Spritzer) hums with an Audio Research amp amd not with a Studer amp? Quote Link to comment Share on other sites More sharing options...
ktm Posted February 27, 2012 Report Share Posted February 27, 2012 Interesting - is that why the SRD-7 Spritzer (and pre-Spritzer) hums with an Audio Research amp amd not with a Studer amp? The other problem is that some amps have a bit of background hum thats hard to notice with speakers, but really is noticable with a transformer box. My ARC vt60 (tubes) has this issue. 20 year old tube amps would take a lot of work to rid yourself of any hum. I have since splurged for some Stax energizers. Problem solved. I had an old H/K receiver from about 1980 that worked great, also used a Rotel rb980 SS amp that worked well. Quote Link to comment Share on other sites More sharing options...
spritzer Posted February 27, 2012 Report Share Posted February 27, 2012 The hum can be either the bias supply's lack of a transformer causing hum or just residual hum in the amp. Older amps. especially tube amps, are very prone to hum. AC heater wiring just adds to this issue. Quote Link to comment Share on other sites More sharing options...
John Buchanan Posted February 28, 2012 Report Share Posted February 28, 2012 Now I remember, Birgir - you mentioned the transformer solution in the past. Sorry, old brain! Quote Link to comment Share on other sites More sharing options...
decoherent Posted March 6, 2012 Report Share Posted March 6, 2012 Spritzer or anybody else havng already done this, when implementing the BIAS for the stax daphragm, you need to set one resistor connected between each stator and bias 0V to have the ias voltage betwen the diaphragm and the stator (e.g. 10Mohm). Do you still need an extra resistor (5Mohm has been suggested) in series with the bias voltage and the diaphragm in this case? Apologies if I'm getting this completely wrong but, how they say, if you don't ask you will be stupid for ever. Thanks. Quote Link to comment Share on other sites More sharing options...
spritzer Posted March 6, 2012 Report Share Posted March 6, 2012 I wouldn't bother with those resistors and keep the 5M resistor as well. It costs nothing and if something goes horribly wrong it will kill most of the bias voltage. I would place output resistors (5K1) if you want extra protection but there is no need for the 10M units. Quote Link to comment Share on other sites More sharing options...
decoherent Posted March 6, 2012 Report Share Posted March 6, 2012 Mmh... not sure I understand how the whole thing works then. We need 580V between the diaphragm and each stator. To do this we need to connect the diapraghm to the +580V and the stator to the 0V. As we have two stators they will be both connected together to the bias 0V shortcutting the signal output. I'm using a tube PP amp plugging the stator to the OPT primary connections. I'm going to duoble the 300ACV from the B+ tranformer and use it as bias. This is why I thought it was necessary to have the two 10mohm resistors to separate the two stators, still providing a ground rference for the bias, and was puzzled only about the extra 5Mohm resistor between Bias V+ and diaphragm you seem to suggest for security reason. To give an example please have a look at the secodn schematic in the auridux page: http://dddac.de/tp08.htm The only difference in my case is that I can't take the bias from the B+ as it is too low and need to source it via a doubler. Thanks. Quote Link to comment Share on other sites More sharing options...
spritzer Posted March 6, 2012 Report Share Posted March 6, 2012 The output on the stators is AC but the polarizing voltage is DC. The only thing the bias does is to set the potential of the diaphragm so it can be pushed and pulled by the AC voltage on the stators. The ballast resistor for the bias supply is used to set the diaphragm to constant charge for lowest distortion but in reality it acts much more as a safety feature. The diaphragm is an open circuit in essence so if something were to close that circuit the ballast resistor would drop most of the voltage. What you are doing is something rather different and those 10M resistors are used to balance out the output stage and to drain the output caps. Quote Link to comment Share on other sites More sharing options...
Maxvla Posted March 9, 2012 Report Share Posted March 9, 2012 (edited) Staxusa.com (Yama's) has brown arcs apparently. They didn't reply to my email but I ordered a pair expecting black but got brown. All fixed: Edited March 9, 2012 by Maxvla Quote Link to comment Share on other sites More sharing options...
ujamerstand Posted March 9, 2012 Report Share Posted March 9, 2012 congrats! Quote Link to comment Share on other sites More sharing options...
HeadphoneAddict Posted March 9, 2012 Report Share Posted March 9, 2012 Staxusa.com (Yama's) has brown arcs apparently. They didn't reply to my email but I ordered a pair expecting black but got brown. All fixed: So, how much was the total damage for the phones and new parts? Quote Link to comment Share on other sites More sharing options...
Maxvla Posted March 9, 2012 Report Share Posted March 9, 2012 All said and done, $1755. Not the best deal, but not bad. The mint pairs on Audiogon go for around $1750-1850, and with new leathers and a body that is free from any dings or dents, this one is nearly mint condition now. I cleaned out any hairs or dust from the driver area while I had the pads off. Quote Link to comment Share on other sites More sharing options...
spritzer Posted March 9, 2012 Report Share Posted March 9, 2012 Not a bad price at given how much people are willing to pay for fubar sets. As if there was ever any doubt but the 007 Mk1 sounds great with the KGSSHV. Quote Link to comment Share on other sites More sharing options...
johnwmclean Posted March 22, 2012 Report Share Posted March 22, 2012 Bit the bullet and sealed the deal on these - Mint MK1’s S/N 70060 Quote Link to comment Share on other sites More sharing options...
Beefy Posted March 22, 2012 Report Share Posted March 22, 2012 I saw those on Canuck Audio Mart the other day. Nice buy! Quote Link to comment Share on other sites More sharing options...
manaox2 Posted March 22, 2012 Report Share Posted March 22, 2012 Bit the bullet and sealed the deal on these - Mint MK1’s S/N 70060 Nice! Quote Link to comment Share on other sites More sharing options...
n3rdling Posted March 22, 2012 Report Share Posted March 22, 2012 Are you building a KGSSHV to pair with them? Quote Link to comment Share on other sites More sharing options...
johnwmclean Posted March 22, 2012 Report Share Posted March 22, 2012 (edited) Thanks guys! They’ll be sitting on the shelf for a while before I can finish my KGSSHV... EDIT: n3rdling I just missed your post by a hair, I”m well into the build, I have a mass of parts in boxes and panels that are 95% complete as FPE files ready to hand over to Cam-Expert for some wallet haemorrhaging. Edited March 22, 2012 by johnwmclean Quote Link to comment Share on other sites More sharing options...
The Monkey Posted March 22, 2012 Report Share Posted March 22, 2012 Do you have any stat amp you can use in the meantime? Quote Link to comment Share on other sites More sharing options...
johnwmclean Posted March 22, 2012 Report Share Posted March 22, 2012 I’ve got no rig in the meantime Monkey, all my dynamic rigs been sold off, kind of a limbo for a while at least. Quote Link to comment Share on other sites More sharing options...
The Monkey Posted March 22, 2012 Report Share Posted March 22, 2012 I’ve got no rig in the meantime Monkey, all my dynamic rigs been sold off, kind of a limbo for a while at least. Well, first of all, congrats, it looks like you got a great O2. Secondly, you might consider getting an SRM1/Mk2 or similar amp to listen through in the interim. mmm...mint O2 mk1.... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.