[Bassman999]

I wish I could cross breed an s500 and a 668. The lows on the S500 together with the openness and highs of the 668 would be a great combo.

Yeah the JVC S500 has no depth to it, and feels all in my head.
I find it slightly claustrophobic really, except for rap and R&B
 
I am shopping for phones for an open sound for jazz etc...

 

[Th3l4st0ne]

If you can build a circuit able to support it, the LM6172 is one of the best I ever heard. But then, for a portable amp, it's going to eat trough batteries like an Head-Fier goes through headphone.

 

[Bassman999]

  If you can build a circuit able to support it, the LM6172 is one of the best I ever heard. But then, for a portable amp, it's going to eat trough batteries like an Head-Fier goes through headphone.

does that mean its a more powerful chip, or just uses more?

 

[Th3l4st0ne]

  does that mean its a more powerful chip, or just uses more?

It runs at a higher voltage and is picky about the circuit: you can't dump it in a cheap Cmoy and hope it sound well. It does seems to have a bit more gain, but that may be a side effect of the 30v I'm dumping in it.

 

[Bassman999]

  It runs at a higher voltage and is picky about the circuit: you can't dump it in a cheap Cmoy and hope it sound well. It does seems to have a bit more gain, but that may be a side effect of the 30v I'm dumping in it.

30 V is A LOT lol...much more headroom

 

[Th3l4st0ne]

  30 V is A LOT lol...much more headroom

Yea, it's a high-bandwidth chip, the main reason it's so picky. But I think it can run decently on 18-20v, check the spec sheet it should be writen there. Otherwise I had OPA2132, AD825 and one of those jellybean chips, the 2132 sounded great at 16-18v, but the LM is just stellar when the layout works.

 

[Bassman999]

  Yea, it's a high-bandwidth chip, the main reason it's so picky. But I think it can run decently on 18-20v, check the spec sheet it should be writen there. Otherwise I had OPA2132, AD825 and one of those jellybean chips, the 2132 sounded great at 16-18v, but the LM is just stellar when the layout works.

Could I take my cMoyBB 2.02 and just series an extra 9v batt in there to run the 2132?

 

[bootdsc]

Just drop in a jrc4556 and run off any voltage battery using a step up/down voltage converter set to what ever voltage you like(i run mine at 10v) 

 

[Bassman999]

  Just drop in a jrc4556 and run off any voltage battery using a step up/down voltage converter set to what ever voltage you like(i run mine at 10v) 

Mine came with OPA2227P
Without comparing it to others I think it sounds decent.
 
Where do I get a step-up that fits inside this lil case?

 

[bootdsc]

Polulu is where i get em, i have used quite a few in loads of projects. You want one with a vary high switching frequency so you don't have any audible noise bleed through the ground channel. 
Here is a link to the one i have used the most http://www.pololu.com/product/2120 this is limited to 12v but they have other models that are made for higher voltage output. If 12v is enough here is a version with a fixed output thats half the price http://www.pololu.com/product/2117 

 

[Bassman999]

  Polulu is where i get em, i have used quite a few in loads of projects. You want one with a vary high switching frequency so you don't have any audible noise bleed through the ground channel. 
Here is a link to the one i have used the most http://www.pololu.com/product/2120 this is limited to 12v but they have other models that are made for higher voltage output. If 12v is enough here is a version with a fixed output thats half the price http://www.pololu.com/product/2117 

Ok I have a few questions.
How does this wire into the main board?
Can I still use external psu with this step in there?
 
Thanks for the links!

 

[Bassman999]

  Ok I have a few questions.
How does this wire into the main board?
Can I still use external psu with this step in there?
 
Thanks for the links!

I just got an answer to the 2nd question by reading the specs , that input V cannot exceed output V for fixed value, but can be for the variable ones.

 

[Bassman999]

Last question is how much voltage can the rest of the cMoy circuitry handle if I switch the opamp and use a step-up?

 

[Bassman999]

  Yea, it's a high-bandwidth chip, the main reason it's so picky. But I think it can run decently on 18-20v, check the spec sheet it should be writen there. Otherwise I had OPA2132, AD825 and one of those jellybean chips, the 2132 sounded great at 16-18v, but the LM is just stellar when the layout works.

Does the higher V circuitry and opamp benefit the higher impedance cans?
I have a pair of 600 ohm 990s

 

[bootdsc]

Well i only use batteries with cmoy's because the power supply will add a lot of noise unless its filtered but then you are getting way to complicated for a simple cheap cmoy type amp. Maybe i left out a key detail, i use a 3.7v lipo with the step up converter and a li po charger with all of the portable amps i have built. Depending how much space i have and if the battery can be easily removed ill ether use a usb lipo charger or external charger. I could never understand why people are willing to pay for disposable batteries especially 9v's having such a low ma rating.