jack Posted January 31, 2018 Report Share Posted January 31, 2018 Cryo’ing should slow it down a bit.Is it sarcasm or sth. I do not understand?Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
nopants Posted January 31, 2018 Report Share Posted January 31, 2018 do you know how the opamp is being used?Sent from my Pixel 2 XL using Tapatalk Quote Link to comment Share on other sites More sharing options...
spritzer Posted January 31, 2018 Report Share Posted January 31, 2018 Let's not dwell on the specifics of how something actually works. 1 Quote Link to comment Share on other sites More sharing options...
wink Posted February 1, 2018 Report Share Posted February 1, 2018 Yeah, if it sounds good doesn't necessarily mean it is good...... Quote Link to comment Share on other sites More sharing options...
jack Posted February 1, 2018 Report Share Posted February 1, 2018 1 hour ago, wink said: Yeah, if it sounds good doesn't necessarily mean it is good...... True! If it sounds good does not necessarily mean it will taste good ;-) Since good is subjective what does good mean to you in audio gear? in what area doen an opamp has to excel in order to be qualified as good? Quote Link to comment Share on other sites More sharing options...
JimL Posted February 1, 2018 Report Share Posted February 1, 2018 2 hours ago, jack said: in what area doen an opamp has to excel in order to be qualified as good? Depends on what its function is. As Kevin Gilmore points out, for a servo, an op amp with virtually no offset current (JFET rather than bipolar) and low temperature drift, that is slow (since the servo is monitoring for DC offset and is deliberately slowed down anyway), is good. OTOH may sound like crap as an amplifier, where the requirements for "good" are significantly different. 1 Quote Link to comment Share on other sites More sharing options...
Helium Posted March 5, 2018 Report Share Posted March 5, 2018 Did anyone run KSA5 at 30VDC? I like all my dynamic amps running at 30VDC. I'm scared a bit to fire it up. Don't want to fry anything. Balanced version was more difficult and expensive to make than I expected. P.S. I'm using OPA445 and G5V-2-H1-DC24 relays. And all other components are according to BOM and PCB silkscreen. Quote Link to comment Share on other sites More sharing options...
rumina Posted March 5, 2018 Report Share Posted March 5, 2018 do you made a balanced ksa5 with two boards? some pictures would be nice :-) Quote Link to comment Share on other sites More sharing options...
Helium Posted March 5, 2018 Report Share Posted March 5, 2018 I'm making it. Boards are ready, paired with 2xGRLV and nice amb's deltas. Cases are not)) Quote Link to comment Share on other sites More sharing options...
hy2a3 Posted March 26, 2018 Report Share Posted March 26, 2018 Anyone have a Kevin's KSA5 bare board to sell? Waiting for all my parts to arrive, intending to build on an Ebay Chinese board clone by Zero Zone. Thought better and will not use; I want to be certain that the board I use have 2oz of copper. Thanks. Quote Link to comment Share on other sites More sharing options...
grendel23 Posted March 26, 2018 Report Share Posted March 26, 2018 I used a Zero Zone board. I don't know the weight of the copper, but the board was nicely made. Quote Link to comment Share on other sites More sharing options...
hy2a3 Posted March 27, 2018 Report Share Posted March 27, 2018 Thanks for the ZeroZone experience. Got did get reply from Ebay seller "DiyTalent86", the Zero Zone Assembled KG KSA5 board is 1 oz copper. Quote Link to comment Share on other sites More sharing options...
Pars Posted March 27, 2018 Report Share Posted March 27, 2018 (edited) Did a quick search back for copper weight and saw the 3oz recommendation. Ran across the special audiophool cable that blew up some poor guys actual KSA5 and found that those fucks are still in business! Revelation Audio Labs jeebus... Edited March 27, 2018 by Pars 2 Quote Link to comment Share on other sites More sharing options...
hy2a3 Posted March 27, 2018 Report Share Posted March 27, 2018 Head-Case.org amazes me. Just added to my religious lexicon. Anyway, Is Dr. Kevin Gilmore's KSA5 Gerber file locked away in a vault? Can't seem to locate the gerber zip to build a single board to myself. Will cost $$$, but I need to do this right avoiding the Chinese clone temptation. Help anyone, if the zip is still open to private use (not commericial). Quote Link to comment Share on other sites More sharing options...
Pars Posted March 27, 2018 Report Share Posted March 27, 2018 Look in the Stax thread for the current archive location.Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
penmarker Posted March 28, 2018 Report Share Posted March 28, 2018 10 hours ago, hy2a3 said: Head-Case.org amazes me. Just added to my religious lexicon. Anyway, Is Dr. Kevin Gilmore's KSA5 Gerber file locked away in a vault? Can't seem to locate the gerber zip to build a single board to myself. Will cost $$$, but I need to do this right avoiding the Chinese clone temptation. Help anyone, if the zip is still open to private use (not commericial). There ya go https://drive.google.com/drive/folders/0B_iJFfZStuVhSE5nOHBVdTByR1k?usp=sharing Quote Link to comment Share on other sites More sharing options...
hy2a3 Posted March 28, 2018 Report Share Posted March 28, 2018 1 hour ago, penmarker said: Thank You. Wow, Dr. Gilmore's contribution is overwhelming. Quote Link to comment Share on other sites More sharing options...
davve Posted June 11, 2018 Report Share Posted June 11, 2018 I was wondering if it is okay to use 47pf or 100pf instead of the 33pf's. Thanks Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 11, 2018 Author Report Share Posted June 11, 2018 you will effect the frequency response. best to use the right part in this case. Quote Link to comment Share on other sites More sharing options...
davve Posted June 19, 2018 Report Share Posted June 19, 2018 I bought my kit from the link below, it is your version?But i was wondering, on the board it says 2x 10k ohms resistors and 2x 1k ohm resistors. But i got 4x 10k ohm resistors. https://www.ebay.com/itm/Power-supply-board-for-KG-version-KSA5-headphone-amp-PSU-DIY-kit-and-finished/122365758658?hash=item1c7d914cc2:m:mfcUM96JgKu8Wbo08L6PZFw Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 19, 2018 Author Report Share Posted June 19, 2018 Yes that is one of my layouts, not in a position to look up schematic/board at the moment. Quote Link to comment Share on other sites More sharing options...
Pars Posted June 20, 2018 Report Share Posted June 20, 2018 10 hours ago, davve31 said: I bought my kit from the link below, it is your version?But i was wondering, on the board it says 2x 10k ohms resistors and 2x 1k ohm resistors. But i got 4x 10k ohm resistors. https://www.ebay.com/itm/Power-supply-board-for-KG-version-KSA5-headphone-amp-PSU-DIY-kit-and-finished/122365758658?hash=item1c7d914cc2:m:mfcUM96JgKu8Wbo08L6PZFw I guess I get the allure of kits from ebay for the cheap prices, assuming the components are a) genuine, and b) decent quality. However, buying a kit and then coming on here without apparently doing a modicum of research first is very bad form. The links to Kevin's board files and schematics/other files are here, but might require a bit of digging. Since that vendor supplies both kits and built units (for a whopping $10 more), one might assume that they build with the same parts as they supply in the kit, and it might not matter whether you use a 1K or 10K resistor in the 2 spots. If you're worried about it, then use some 1K for those two positions. But otherwise, the appropriate head-case response is... 1 Quote Link to comment Share on other sites More sharing options...
davve Posted June 20, 2018 Report Share Posted June 20, 2018 6 hours ago, Pars said: I guess I get the allure of kits from ebay for the cheap prices, assuming the components are a) genuine, and b) decent quality. However, buying a kit and then coming on here without apparently doing a modicum of research first is very bad form. The links to Kevin's board files and schematics/other files are here, but might require a bit of digging. Since that vendor supplies both kits and built units (for a whopping $10 more), one might assume that they build with the same parts as they supply in the kit, and it might not matter whether you use a 1K or 10K resistor in the 2 spots. If you're worried about it, then use some 1K for those two positions. But otherwise, the appropriate head-case response is... My apology then for using the krell thread. I have read the thread and was just wondering if there been some changes. Cause 10k or 1k input for the op27 is some diffrence. Perhaps i like to solder? Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 20, 2018 Author Report Share Posted June 20, 2018 (edited) It really depends on which resistors were changed. If they gave you a schematic, please post it. Edit: found the schematic. you can replace the 1k with 10k resistors. The power supply will come up a bit slower, but it will otherwise work. Edited June 20, 2018 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
Pars Posted June 21, 2018 Report Share Posted June 21, 2018 Perhaps I was a bit harsh? The 1K resistors I see on the schematic I have are on the collectors of Q1/Q2, feeding the + inputs on the error amp. Not sure if going 10K here would make any difference whatsoever. ksa5psschem.pdf Quote Link to comment Share on other sites More sharing options...
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