[luvdunhill]

Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif Caution: Pay extra attention to the Q15's temperature. Add adaquate heatsink to prevent it from overheating, add external heatsink if necessary. Try not to use a modded amp in a warm spot (in a pouch, under the sun etc). I have just encounted the first Q15 failure, though the amp is of a early version with different transistors than the current MKII.

any recommended heat sink patches? the link you posted in reference to this is dead, so I couldn't see the kit you were referring too..

oh and also, do you know the resistor size and power rating of R35/R34?

 

[luvdunhill]

sounding great!

 

[AudioCats]

hmmmm, not sure where to find small patches, digikey has the big ones but they are way big @ $70 per sheet.

hehehe, so the RTE's do fit. What op-amp are you using?

 

[luvdunhill]

Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif hmmmm, not sure where to find small patches, digikey has the big ones but they are way big @ $70 per sheet. hehehe, so the RTE's do fit. What op-amp are you using?

yeah, I've seen the big ones at Digikey... I'm probably going to see if I can get a sample

Right now, I'm using LMH6642MA. I tried the same Analog opamps as you did, as well as the AD8610. For some reason, I cannot fault the LMH6642MA at this point, and battery life is good, so I just left it in.

With the RTE, you just have to be very creative with the lead bending. With the one closest to the back of the board, you need to desolder one of the HV caps and sort of tilt it a bit. You also have to file down one of the supports at the front of the case.

I'd love to try another headphone with this amp, so either finding a cable to hack up or making an adapter is my next goal, as well as a small shunt regulated DC supply.

 

[borisov57]

Hello,

I just changed Toshiba opamps for OPA827. Sound has changed a lot. Whole spectrum is cleaner with more details in midrange and sound is more 3D. Notes decays longer.

 

[HeadphoneAddict]

With the AD8599 and Super Fat Cat ++ (requiring external battery pack due to caps in the battery bay), the SR-001 sounds as good as SR-003 on a good desktop amp. So far I have been very impressed after another 500 hours of burn-in (just in case). It is much better extended at both ends of the spectrum than stock, without the midrange hump. And, it is smoother and more refined than the previous SFC which still allowed 2 parallel Lithium batteries inside. Bravo!

 

[borisov57]

AD8599 is great op-amp, but I did not like it too much in SR-001. I had it in amp for only one day. Maybe I should give it another chance and some more time to settle in. But OPA827 sounds great from first second. Low level detail and ambience retrieval is unbelievable.

 

[sclee]

No updated on the thread long time.

I bought a UM3 try to replace SR001 but the quality of moded sr001 is better that um3 much more.


About the power.

I bought 2 pcs Ultrafire Li ion battery, supply to sr001, compare as power supply and Li ion battery.

The Power supply with large cap and good buffer cap should better that Li ion.

Power supply:

1. Must non-regulator power supply. At least 400ma output
2. set 4.5v with one 1W diode
3. 2 Elna Audio 3600uf Cap, one WIMA Black 0.15uf Cap and one 0.1uf MIT Multicap

The output voltage of power supply is 3.25V

The bass quality and speed will better that Li-ion, but Li-ion slightly more clear that power supply.

Mobility of Power supply is very poor, so that i want to try big Li-ion supply with good buffer cap.

I could like to found High volume Li-ion batterys and recharge IC, build a dual power battery box with at least 15hour run time.

 

[borisov57]

I guess we need something better than unregulated supply. Something like Jung regulator with low Zout and low noise.

Sclee:
I have listened to UM2 once, but for me it is not even close to SR-001.

 

[EFN]

I have a virgin SRM driver heading my way......can't wait to start modding them

 

[EFN]

Almost done. Just waiting for a few more caps to arrive.

Still a bit of work on the C6

 

[borisov57]

Wow, that looks cool. What are those yellow caps? Will they fit in enclosure?

 

[EFN]

Quote:

Originally Posted by borisov57 /img/forum/go_quote.gif Wow, that looks cool. What are those yellow caps? Will they fit in enclosure?

The yellow caps are custom fabricated by Octave Audio Malaysia. Yes they barely fit the enclosure. But I am afraid I will run out of space very soon once the C6 caps are being worked into them.

Cheers

 

[fishpatrol]

I may just not have found it, but has anyone done a write up comparing a modded SR-001 with a stock SR-005?

 

[HeadphoneAddict]

catscratch did something similar with a modded SR-001 and a SR-003 on a SRM-3xx series amp, and I chimed in with my SR-003 on an SRM-1 Mk2 Pro.

Review: AudioCats-modded Stax SR-001 MkII, vs Stock SR-001 and SRM-313/SR-003 - Head-Fi: Covering Headphones, Earphones and Portable Audio

Since his review where I commented, I have had mine taken up to the next level, and it is now better than SR-003 on any amp I still have except for my Woo GES which beats it.