[SpudHarris]

The LT1363 never stayed too long in my gear as I always liked others more. My favourite amp with rolling capability is the Fi-Quest and I have yet to find anything better sounding than OPA1641's in this. I will swap them out tonight and give the 1363's a good listen, I know they were always one of Leeperry's favourites but I just never got it. Maybe my ears have matured now, we'll see....
 
My Favourites are OPA1641 / AD797B / OPA602BP + CM / ADA4637-1BRZ / OPA827 in that order.

 

[kiteki]

Thanks for sharing SpudHarris, it was your picture of the LT1363 in the ground channel in the Warbler which made me buy two of them in the first place, so I am eternally grateful.

 

[SpudHarris]

Glad to help

Can't remember when I last used them in ground. I prefer the ISL5002 in the P4....

The LT1363's are in my Fi-Quest and I will give them a good listen in L/R tonight, I've had a quick listen but will report back tomorrow.

I've said this before but I am not a massive fan of LT chips in L/R. Nearest I got was LT1122

 

[kiteki]

If you try them in the Warbler, use them x2 in L/R, a quality buffer x2, bypass virtual, bypass ground.

 

[SpudHarris]

Will give it a try. Results in Fi-Quest are good but not a patch on OPA1641....

Will get the P4 out tomorrow and try.

 

[zilch0md]

Oh Nigel!   Are you still rolling opamps?    
 

 
I was doing great until I cracked open my PB2 a couple of weeks ago, for the first time in about three months!  
 
It wasn't long before I got swallowed up in a downward spiral there for a couple of days - I'd call it a lost weekend, for sure - but when I started to twitch all over and get convulsions, I managed to pull myself together and call the op-amp rolling obsession prevention hotline.  They talked me down.  Good people, those volunteers.   
 
The next day, I flushed all my spares down the toilet. You should think about it Nigel - seriously.
 
Your friend,
 
Mike

 

[kiteki]

That makes me feel better the OPA627SM's I bought are not that costly in alcohol terms.

 

[Mad Max]

Oh Nigel!   Are you still rolling opamps?    



I was doing great until I cracked open my PB2 a couple of weeks ago, for the first time in about three months!  

It wasn't long before I got swallowed up in a downward spiral there for a couple of days - I'd call it a lost weekend, for sure - but when I started to twitch all over and get convulsions, I managed to pull myself together and call the op-amp rolling obsession prevention hotline.  They talked me down.  Good people, those volunteers.   

The next day, I flushed all my spares down the toilet. You should think about it Nigel - seriously.

Your friend,

Mike

I'll sell you some of my spares at bargain prices.
:veryevil:

 

[SpudHarris]

Quote:

Oh Nigel!   Are you still rolling opamps?    
 

 
I was doing great until I cracked open my PB2 a couple of weeks ago, for the first time in about three months!  
 
It wasn't long before I got swallowed up in a downward spiral there for a couple of days - I'd call it a lost weekend, for sure - but when I started to twitch all over and get convulsions, I managed to pull myself together and call the op-amp rolling obsession prevention hotline.  They talked me down.  Good people, those volunteers.   
 
The next day, I flushed all my spares down the toilet. You should think about it Nigel - seriously.
 
Your friend,
 
Mike

 
LOL
 
Mike, I'm afraid I fell off the wagon last night but only for the LT1363 trial.
 
I listened for 3 hours and have to say they sound quite nice in my Fi-Quest but they are not the holy grail. Will try in the P4 tonight just in case.... I've been listening exclusively with my HE-6 of late and I think I've been a bit spoiled. I use a Topping TP60 speaker amp to feed them and boy does the extra power make a difference, none of my other amps/phones compare with the HE-6/Topping combo.
 
Will try the P4 and Fi-Quest with easier to drive phones for a fair comparison.

 

[kiteki]

The HE-6 is quite different than the tiny Vsonic and TWFK IEM's I used to listen to the LT1363, just sayin'...
 
 
It doesn't deliver the power of a speaker amp, or the transparency of an OPA16XX, but what it does do for me, it does extremely well.

 

[AnAnalogSpirit]

.

 

[George_63]

Could anyone tell me if 3.9k resistors are ok for an A class biasing of OPA2227? What resistor value would be the optimal for an operating voltage of 15V?
Thanks...
 

 

[Avro_Arrow]

Resistors are not good for class A biasing...A CCS is the preferred method.

 

[jcx]

resistors can be OK depending - like everything in engineering
 
if you have high supply V re the actual headphone drive requirement simple R loading can be fine
 
also depends on whether you're trying for full Class A directly driving the headphone or if you're talking about a op amp + buffer circuit
 
simple R do load the op amp output more, reduce small signal gain - but if the added R are a much higher value than the headphone Z, within op amp load spec, then their added load may not really matter
 
if you need greater efficiency, are going to swing nearly to the amp Vsupply limits then active ccs is better - and led/bjt or bjt "ring of two" waste much less V than the (locally to head-fi) faddish jfet ccs

 

[kiteki]

A qiuck question... are there any inherent flaws in using a chip like AD797 as a buffer?  If it sounds good, y not?