Northern Oak 0 Report post Posted February 24, 2003 hi, I was looking at Chu Moy's Portable Amplifier Design at headwize.com and wanted to DIY. However, I was not able to get the Burr-Brown OPA134PA-ND opamp locally in Singapore. Could any kind soul here provide some directions? I don't really want to order online unless necessary. On the other hand, would anyone recommend a suitable audio-specific opamp that can be used as a substitute and purchased in Singapore easily? Thanks. BTW, Rameish, don't worry, I am still very interested in the Porta Corda II but I got to find some time to be able to get to your place for the audition. Share this post Link to post Share on other sites
jtfoo 0 Report post Posted February 24, 2003 (edited) Hi Northern Oak, The Dual version of OPA134 is the OPA2134. Which means the OPA2134 has the exact same spec as the OPA134 and most would say the same sound. And the bonus is the OPA2134 has dual channel that would save yourself space as you would need only one chip as oppose to two. The OPA2134s are available from RS component or Farnell BTW my cmoy uses the OPA2134.. Edited February 24, 2003 by jtfoo Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted February 24, 2003 Thanks alot. BTW, I thought the OPA2134 may introduce thermal crosstalk distortion? Share this post Link to post Share on other sites
jtfoo 0 Report post Posted February 24, 2003 Thanks alot. BTW, I thought the OPA2134 may introduce thermal crosstalk distortion? ??? What's that? Share this post Link to post Share on other sites
yekim 0 Report post Posted February 25, 2003 hi, i was looking for this sometime back but have set aside the project in favour of a tube headphone amp - probably the morgan jones amp - but when i was looking for this - i shot an email in the direction of TI and they sent me info on how i could get sample pieces - free. so id suggest emailing texas instruments in singapore - tell them what you need and they should get back to you with instructions which could have you getting closer to your amp Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted February 26, 2003 hi yekim, I have actually ordered the units from RS Components, cost me $4.14 per piece. The online catalogue mentioned that they have the OPA132 but they called me later and said it has been discontinued. Farnell also carries the OPA134PA and sells them at $4.02. However, if your order is less than $50, then you will have to pay delivery charge of $10. Regarding the tube amp that you are doing, it is difficult, you have got me interested in it as well. Care to share some experience? Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 26, 2003 whats the delivery charge for RS components like? Share this post Link to post Share on other sites
jtfoo 0 Report post Posted February 26, 2003 whats the delivery charge for RS components like? No charges Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted February 26, 2003 hi jtfoo, I am not really sure about the thermal crosstalk distortion, just that it was mentioned in Chu Moy's article. I guess it may be distortion or interference due to thermal dissipation from both the opamps in the same package. Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted February 26, 2003 Yup, absolutely no charge and I felt that the online catalogue from RS Components is more friendly than Farnell's. Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 26, 2003 WOW!! REALLY?? sh*t man. why didn't anybody tell me about this online SLT earlier dammit Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted February 26, 2003 Watch it, the prices at RS Components, your online SLT, may be more expensive than the SLT in town. However, it is easier to source for hard-to-find components. Share this post Link to post Share on other sites
ablaze 0 Report post Posted February 26, 2003 noted. thanks for the caveat Share this post Link to post Share on other sites
N@Z 0 Report post Posted February 26, 2003 Good info to know for us closet newbie DIYers... Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted February 27, 2003 I hope I can start with my CMOY circuit tonight but I am still short of the 3.5mm or 1/4" stereo chassis socket. Wonder if anyone knows which shop in SLT sells them, going to rush down from work today to get them. Share this post Link to post Share on other sites