[kwillisjr]

Has anyone tried different op amps in the bugle?  Is there anything I need to look for if I decide to try out various op amps in mine?

[Brinkman]

The search engine is your friend. You'll get a lot of hits with the following:
Terms: op amp, opamp, bugle
Make sure 'Hagerman Technology' is the only box checked to search within.

[Phoca]

I will say that I have tried numerous op-amps and I find no substantial differences (2134, 2107, 2111, etc.).  Differences, yes, but they are swamped by my limited TT and cartridge options (Thorens TD-160 with AT440MLa, Kenwood 4021 w/Grado Prestige Black, and Dual 1219 w/ADC XLMII).  Haven't yet tried a 627, but while I'm sure there's a difference, I'm having a hard time justifying  the cost to try it out.

The bigger influence, IMHO, is using 2134 in the first two positions.  They are quiet and very nice.  I've been using 2137s to extend battery life, which they do nicely, but I get a strong hiss when the volume is turned up.  They just aren't as black as the 2134s.  I've now built a DIY PS which provides 12.1v + and - supplies and first impressions are quite impressive.  I'll probably report later, and maybe will test out the different op-amps again.

Carl

[G E]

I use AD8620 in the third position.  They have lower voltage rail max +-12vdc, if memory serves so you will need to sub 12 VDC regulators for the spec'd 15 volt ones in the plans.  This is a dynamic opamp and is symbiotic with my Grado Reference Sonata 1 cartridge.  A friend brought over a mid 1970's Japanese pressing of Return to Forever's Romantic Warrior and both our jaws hit the floor.  If only all vinyl was this quiet and dynamic!  The Bugle is a performer way beyond its price point.