[bigfishe]

Whats the best op amp for the bugle aa

[Brinkman]

It would depend on the position in question. Jim has said that the RIAA EQ was designed around the OPA2134, so those op amps should be retained in the first two positions, per design. The final opamp position (a buffer) is up to you. Pat O'Malley has a thread here from a ways back on this topic. This site has some interesting comparisons.

Also, diyaudio.com seems to have the bulk of the chip rollers posting there, so a little research there would turn up many options.

Let us know what you end up trying.

Best.

[reuben]

Even though it is not recommended (because of the bipolar inputs), an OPA2228 or LM4562 in first position lowered the noise floor in my Bugle.

[PatOMalley]

here is that page with comparisons: http://home.comcast.net/~omaille/audio/BUGLE/opamp.html

The LM4562 also went into my headphone amp and Cambridge 640p phono pre. In each case there were better dynamics and space. Nothing else suffered like bass response. Clarity thru the midband was better.

I would solder the first two opamps directly to the board to reduce noise and leave the last as pluggable. There are others to try. I rcvd OPA827 opamp in singles. I got 5 of them from Texas Instruments as samples but have not yet soldered them to an adapter yet. The 827 is supposed to be coming out in duals as OPA2827 but Digikey does not have them yet.

One thing to try is to add a .1uF BlackGate cap to pins 4 & 8 on the bottom of the board.

[bigfishe]

Thanks fellez
I have been looking at the Burson

[Brinkman]

Thanks fellez
I have been looking at the Burson

According to an online acquaintance of mine, the bursons require A LOT of decoupling to sound their best, so you might want consider a pair of 1000uF bypasses if you use the burson.
I have a burson op amp for my Ripper, and a pair of 1000uF Elna Silmic IIs to help it out. However, I won't know how it sounds until I sort out my chassis issues...

[hagtech]

I think someone once reported Bursons do not work well in the BUGLE.  Should be somewhere deep inside this forum...

jh

[Brinkman]

I think someone once reported Bursons do not work well in the BUGLE.  Should be somewhere deep inside this forum...

jh

Right here. Again, I'm not sure if some local decoupling wouldn't have helped out a bit. 

[PatOMalley]

Brinkman,

I should have tried a cap but I had a little back and forth with Burson about the installation and they said sometimes this just doesn't work out. Another far more experienced DIYer tried the Bruson's as well and he didn't like it in the machine.

I wouldn't want to say they won't work, only that they didn't in my case and I may not have got them right. I would think what they wold do is to bring out the sound of the opamp right behind them more than anything, if they are as linear as advertised.

If someone does try them and get them to work out it would be a good addition to the knowledge base.

I think someone once reported Bursons do not work well in the BUGLE.  Should be somewhere deep inside this forum...

jh

Right here. Again, I'm not sure if some local decoupling wouldn't have helped out a bit.

[Brinkman]

For what it's worth, there's a thread at audiokarma by the gentleman who told me of the need for lots of decoupling when using the Bursons. This thread details his efforts:http://www.audiokarma.org/forums/showthread.php?t=185971. His decoupling is just nuts, like 33000uF or so.