bpribadi 0 Report post Posted September 7, 2004 (edited) How much does the OPA627 cost? S$ 37.72 per IC (5% GST included), at Farnell. Means S$ 75.44 per pair. Not sure if Huangyong can help us to get it cheaper from TI China. If he can, we can start a group buy for OPA637/OPA627. I was thinking of getting one if someone can help me fit it on a browndog adapter... No problem, I can help you with it. Really nice amp, bpribadi, btw. Thanks! Edited September 7, 2004 by bpribadi Share this post Link to post Share on other sites
heady 0 Report post Posted September 9, 2004 (edited) Thanks to bpribadi, I just substituted the OPA2134PA with the OPA2228 in my 3 channel CMOY and wow, the difference is startling. Nicely controlled bass with detailed highs. It may sound like less bass than the 2134 but that's because the bass is tighter and more impactful. Good op-amp. Edited September 9, 2004 by heady Share this post Link to post Share on other sites
bpribadi 0 Report post Posted September 11, 2004 I have received the AD8066 (dual) and AD8065 (single) from AD, and I just mounted it on small perfboard as adapter for SO8 > DIP8. I will add my comments of how it sounds once I got time to try it with my amp. Share this post Link to post Share on other sites
heady 0 Report post Posted September 11, 2004 Hi Bram, am listening to AD8620 on my CMOY. Wow, beats the OPA2228 in separation. The musical instruments are nicely placed in a distinct sound stage and not bright thru my DT880. But the 2228 is good value for money since the AD8620 cost approx S$30 each. Unless you get it free that is. Share this post Link to post Share on other sites
bpribadi 0 Report post Posted September 11, 2004 (edited) I should come to your place and try it AD8620 is very good in transparancy and imaging, but too bright for my Grado RS-1. So when paired with a not so bright headphone, it is a very good Op-Amp. Heady, how did you mount them? Have you bought the SO8>DIP8 adapter? Edited September 12, 2004 by bpribadi Share this post Link to post Share on other sites
heady 0 Report post Posted September 12, 2004 I bought them already mounted on the browndog adaptor, from Tangent, paid S$65 for two plus shipping. Ouch!!!! Share this post Link to post Share on other sites
bpribadi 0 Report post Posted September 13, 2004 I have added my small review with AD8066. This is an excellent Op-Amp! Now it stays in my headamp Share this post Link to post Share on other sites
bpribadi 0 Report post Posted September 30, 2004 Added with OPA637 Share this post Link to post Share on other sites
domi33 0 Report post Posted October 4, 2004 bpribadi, I'm curious, can you post a schematic of your "ala Pimeta" ? Thks Share this post Link to post Share on other sites
heady 0 Report post Posted October 4, 2004 domi33, http://www.sgheadphones.net/index.php?showtopic=2571 Share this post Link to post Share on other sites
bpribadi 0 Report post Posted October 4, 2004 Thanks Heady ! The schematic is PPA schematic: http://tangentsoft.net/audio/pimeta/misc/schematic1.pdf The differences: 1. The power supply section, I use voltage regulator. 2. The class A biasing, I use PPA 1.0 jfet cascode. Share this post Link to post Share on other sites
bpribadi 0 Report post Posted October 17, 2004 Added with OPA2107 Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted October 18, 2004 i'm interested in the adaptor that u're using Bram is it DIY or off the shelf? just ordered a few samples from AD including the 8066 to try out on the new amp, but they are all SO8 op-amps Share this post Link to post Share on other sites
bpribadi 0 Report post Posted October 18, 2004 (edited) It is DIY adapter. I cut perforated board, 4x4 holes, and solder all the pins with the SO8. So far, I found it is the easiest way to work with the SO8. 2 months from now, AD will have AD8067 with slew rate 640 V/us, much faster than the AD8065/660 slew rate (180 V/uS), develop with the same process, FastFET, as the AD8065/66. http://www.analog.com/en/prod/0%2C2877%2CAD8067%2C00.html Edited October 18, 2004 by bpribadi Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted October 18, 2004 Bram, can go into more details on how u do the adaptor? maybe on another tread Share this post Link to post Share on other sites