[drewjp]

I cannot afford the Woo Audio of my dreams yet, so I picked up a used Creek OBH-11 off eBay. It did not sound very good with my K701s out of the box. So I figured this is as good a place as any to start scratching the DIY mod itch! I replaced the input caps with Hovland Musicaps, the output caps with Elna Cerafines, and I installed an adapter so that I can roll op amps easily. I also replaced the stock op amp with a BB OPA2134. I also upgraded to a regulated 24V power supply. Here are some pics:




I also have an OPA2107 on the way to try out. 

 

[GreatDane]

Thanks for the pics and happy moding...but this is the portable amps forum.

 

[drewjp]

Sorry about that...I'll report this to an admin to post this in the Full-size forum....

 

[qusp]

nice one, I would look at bypassing the output caps with small films to tighten up the sound. electrolytics are not so hot in the signal path by themselves

 

[drewjp]

Update: I just replaced the OPA 2134 with a OPA 2107.
 
It's a huge leap in sound quality! Whereas I was let down by the narrow soundstage and muffled treble of the 2134, it is all back now! Treble extension, bass extension, bass quickness are all noticeably better with the 2107.
 
I wasn't expecting such a big difference. I am very happy with 2107.
 
It still leaves me wondering what I'm missing by not having dual OPA 627 in there though....

 

[drewjp]

UPDATE: I just replaced the 2107 with dual OPA627!
 
So far I love the sound. My HD 650s have only about 40 hours on them currently, but I can already discern some differences (for the better) from the OPA2107.