bpribadi 0 Report post Posted October 1, 2004 (edited) OPA2228/7 OPA637/627 OPA2107 AD8066/65 Check: http://www.sgheadphones.net/index.php?showtopic=2628 Edited October 1, 2004 by bpribadi Share this post Link to post Share on other sites
dreamie 0 Report post Posted October 3, 2004 OPA2228/7 OPA637/627 OPA2107 AD8066/65 Check: http://www.sgheadphones.net/index.php?showtopic=2628 Thanks for the recommendation. Seems like only the AD8066 is a FET input opamp? Cheers! Share this post Link to post Share on other sites
bpribadi 0 Report post Posted October 3, 2004 All Op-Amps mentioned in my review are Jfet input. Share this post Link to post Share on other sites
dreamie 0 Report post Posted October 3, 2004 All Op-Amps mentioned in my review are Jfet input. Ahh.. I'll try them. Have all the OPAs there with me right now. Thanks! Share this post Link to post Share on other sites
dreamie 0 Report post Posted October 28, 2004 Just swapped the AD8620 into the phono stage. It seems to be clipping now and then, at least that's what I think clipping sounds like. Share this post Link to post Share on other sites
dreamie 0 Report post Posted October 29, 2004 The OPA637 is now in the phono. Seems to be a balance of the OPA2134 and AD8620, albeit with more bass. The "clipping" sound disappeared when the AD8620 is removed. Perhaps my supplies are approaching its limits. (+- 12V supplies from a SMPS, so voltage should be closer to +-13V, the limits of AD8620, since the SMPS is not really loaded) bpripadi, my findings have been quite consistent with yours. I would like something which is slightly brighter... and it seems to be the AD8066 from your thread. Anyone got spare AD8066s? Willing to exchange for opamps? hehehe... Still got some AD797 and AD8610/20s with me. Share this post Link to post Share on other sites
jtfoo 0 Report post Posted October 29, 2004 The AD8620 can work close to it's spec max of 13 V. I've tried +-13.xx V with an overcharged SLA battery before.. Maybe it's oscillating? You can add some fast bypass caps to gnd near the V+ & V- pins of your opamps. Share this post Link to post Share on other sites
dreamie 0 Report post Posted October 29, 2004 The AD8620 can work close to it's spec max of 13 V. I've tried +-13.xx V with an overcharged SLA battery before.. Maybe it's oscillating? You can add some fast bypass caps to gnd near the V+ & V- pins of your opamps. Ok.. have some spare 0.47uF stacked films around... .. just wondering if 0.47uF is enough. Is the Cerafine alright? Though being an electrolytic it should be faster than normal electrolytics. Have some spare 10uF Cerafines lying around too... Share this post Link to post Share on other sites
jtfoo 0 Report post Posted October 29, 2004 The AD8620 can work close to it's spec max of 13 V. I've tried +-13.xx V with an overcharged SLA battery before.. Maybe it's oscillating? You can add some fast bypass caps to gnd near the V+ & V- pins of your opamps. Ok.. have some spare 0.47uF stacked films around... .. just wondering if 0.47uF is enough. Is the Cerafine alright? Though being an electrolytic it should be faster than normal electrolytics. Have some spare 10uF Cerafines lying around too... For more effectiveness, or kiasu, to stabilise you opamp, you can use your 10uF cerafine connect as close to the V+ and V- pin of the opamps, and bypass the cerafines with another fast polypropylene, say 0.1uF. Share this post Link to post Share on other sites
