[randytsuch]

You don't need AA batteries installed, if you are feeding it power through the external jack, I do it all the time.

The headphones are plugged in, right? I've forgotten to do that more then once.

Randy

 

[fidele-caput]

Strange. Mine won't turn on if there is no battery. It could, only if I short the battery poles.

The phones are plugged at all time. BTW, I've got a newish model here.

 

[randytsuch]

Quote:

Originally Posted by fidele-caput /img/forum/go_quote.gif Strange. Mine won't turn on if there is no battery. It could, only if I short the battery poles. The phones are plugged at all time. BTW, I've got a newish model here.

That is strange, I haven't had batteries in mine for a while, just running off an AC adapter.

I am recasing mine into a larger box, to accomodate the changes I am making. Just removed the existing power input jack, and converted to a chassis mount one. I also added a switch to turn off power. I lost the power switch because I removed the existing volume pot, and replaced it.

Reason I bring this up is that I looked a little at the power in when I did this, and I think the battery and the external power in go to the same place, at least in my version, which is an older one. I bought it used a few years ago. So, as far as I can tell, the SRM can't tell if it is running from batteries or external power, it just knows that power is coming in from somewhere.

BTW, what do you mean when you say you're shorting the battery poles?

Randy

 

[fidele-caput]

Quote:

Originally Posted by randytsuch /img/forum/go_quote.gif Reason I bring this up is that I looked a little at the power in when I did this, and I think the battery and the external power in go to the same place,

You're right. I was wrong. I got it mixed up with my crappy power cable. lowered the usb 5V (resistors divider) to 4.6V and it's not working. I'll just suck it up and use 14500. Thanks mate.

edit. ps: I made two dummy AA batteries to short the poles.

 

[jung]

Is there any NiMH 1/2 AA? If 4 half AA can fit into the 2 AA slots, it would double the voltage to 4.8V for better sound, but maybe cut the play time to half.

 

[Questa]

Hey guys, if I want to use full size phones for ultra fat can srm001, what is you guys suggest?
maybe some of you will say like its not powerful enough, I know that, but what if we don't have other stats amp beside FCU srm001, what stat the phones that the easiest to handle?

 

[krmathis]

^ Something relative small (diaphragm wise) as the SR-X/MK3 Pro maybe? Just guessing, as I have no idea about the power capabilities of the SRM-001.

 

[Questa]

yeah I'm thinking of that also, but they are as rare as a unicorn

 

[AudioCats]

You can also try the wide-ribbon Lambda's. The sound will be a little soft but might not be a bad thing.

 

[borisov57]

Hi AudioCats and all,

I have put OPA1642 in my SRM-001, primary reason was lower consumption than OPA827.
But, oh boy. This is op-amp is made for SRM-001.
It's very low noise and distortion, low input current and high gain translates in sound, which is so good, that........ I am not to good in describing sound, but what I am listening right now is simply breathtaking ( high frequencies too ).

A lot of fun to everyone,

borisov57

 

[marcus1]

Hi Boris

Does the OPA1642 directly replace the stock opamp or do you have to modify it to fit into the existing socket?

Thanks

Quote:

Originally Posted by borisov57 /img/forum/go_quote.gif Hi AudioCats and all, I have put OPA1642 in my SRM-001, primary reason was lower consumption than OPA827. But, oh boy. This is op-amp is made for SRM-001. It's very low noise and distortion, low input current and high gain translates in sound, which is so good, that........ I am not to good in describing sound, but what I am listening right now is simply breathtaking ( high frequencies too ). A lot of fun to everyone, borisov57

 

[borisov57]

Quote:

Originally Posted by marcus1 /img/forum/go_quote.gif Hi Boris Does the OPA1642 directly replace the stock opamp or do you have to modify it to fit into the existing socket? Thanks

In SRM-001 there are pads for dual SMD op-amps like OPA1642. But resistors in power supply filters must be changed also, because of higher supply current (1.8 mA vs. 0.5 mA of stock Toshiba op-amps).

 

[marcus1]

Thanks Boris - just checking; is this the correct part below?
OPA1642AID Texas Instruments Op Amps


Quote:

Originally Posted by borisov57 /img/forum/go_quote.gif In SRM-001 there are pads for dual SMD op-amps like OPA1642. But resistors in power supply filters must be changed also, because of higher supply current (1.8 mA vs. 0.5 mA of stock Toshiba op-amps).

 

[borisov57]

Yes marcus1, that is the one, I am using.

 

[marcus1]

Thanks Boris; last question :*)

In post #94 you described your modification:

"Hello,

Here is picture of changed input and output caps. Input is BG 47u/6V3 NX and output caps are Wima polypropylen 47n/630V. Power supply cap is Epcos X2 100n.
After this photo was taken, I changed four power supply caps (10u/25V) with 100u/25V Rubycon ZLG and bypassed BGs with 68p silver mica."

Does the above (along with the new OPA1642 and resistors in power supply filters) accurately describe your current set-up?

Thanks again