Anyone tried the OPA 2111 ?

Quote:



It will fit no problem Mark as the dip socket has the height to clear the nearby resistors comfortably. You're probably best buying the browndog direct and it will simply be a case of plugging it into your existing socket.

Mike.

PS: I've ordered a couple of AD8620's and will attempt making a contraption which will plug directly into the DIP8 socket

A slighty larger picture

Quote:



Let me know how you get on, I am keen to know your views on the op amp.

Wordsworth

Okay, I just plugged two OPA637s on a browndog adapter into my PIMETA to replace the OPA2111. The first thing I noticed was the HUGE soundstage, much larger than with the OPA2111. Treble is more prominent, and slightly more detailed with the OPA637s. Bass is more controlled, but equal in depth. The OPA637 really brings you back to the usual BB sound, which the OPA2111 departs from. I like the OPA637 a little bit more, but the OPA2111 comes very close. Both are leagues ahead of the OPA2134, OPA2132, and AD823AN. The DT880s are extremely sensitive to changes in the amp, more so than I could have imagined. I'm probably going to have to upgrade to a PPA soon.

Try the AD8620 and let us know how you like it.

Quote:



I've ordered one from Tangent Morsel, is it really "that" good? Seems pretty reasonable at $12 for the chip and $4 for the adapter

Why are more people not using the ad8620? I thought they were well-known to be the best. Is it the price, or the desire to experiment around? I ask because I bought the 8620 without batting an eye based on what I had thought. Now, maybe i should shop around with other chips to find one that suits me?

Personal preference, builder preference, and the belief that more expensive equals better are possible reasons.

Quote:



The 8620 is "cheap" compared to a opa2107 / opa2111 In the UK a 2111 costs $32 compared to the AD8620 at a mere $12 ...... the OPA2107 clocks in at around $28 so if "expensive equals best" the 2111 / 2107 should be flavour of the month?

I prefer to use my ears and in the Chiarra (this cannot be emphasised enough.. CHIARRA... not every application!) OPA2111 / OPA 2107 and AD823 / 712 are superb sounding op amps. I've ordered a few 8620's on Browndogs and can't wait to hear what all the fuss is about

In the meantime I'm listening to an AD OP271 and it's performing admirably...........

AAAAAAARGH!!!! this op amp "rolling" can drive you crazy!!!!

Pinkie.

I "still" reckon the AD712 is the best op amp in the Chiarra but am afraid to mention it here in case it's slagged off as "old fashioned" or "Cheap" I don't give a damn......... the 712 rocks!

The OPA-2107 is and has been my fav for over 15 years in Dual Di-Fet BB OPA's I would avoid the OPA2111 its 2 Volts per uSec slew and 2 MHz GBP place it below the AD-712,OPA-2107 and not much better than the popular 4558. The AD-8620 IMHO is an upgrade to all of these althought I do have a fondness to the Warm non hard sounding AD-712 But you give up detail compaired to these newer devices.

At the moment the OPA 2107 is the best sounding opamp I've heard in the Chiarra amp, obviously I've not heard as many as your goodself, ppl but would you agree that once you get to a certain standard sound quality differences tend to be minor.

Quote:



Hi PPL,

The Op amp utilisation in the Chiarra circuit would appear "theoretically" to have no effect whatsoever on sound quality but swapping op amps has a very pronounced effect on the sound and there is a "very" audible difference (see diagram) This amp seems to respond very noticeably to a change of chip and I wonder why this is the case........ can you throw any light on the matter after looking at the diagram??

My favourite was always the AD823, closely followed by the AD712....... then again, the 2111 sounds valve like with undercurrents of guava floating on a honey base, the 2107 very nice with a hint of nettles dancing on a bed of strawberries with a strong sense of tarmac underpinning the bass, the 2227 could be described as "organic" you can really smell the soil with this op amp and can taste the earth....... 2132 is analytical though the infusion of camomile and aloe vera tame its microscopic view on the proceedings , 2604 warm ,moist and seductive, 2132 integrated, 2134 honky, 2228 organic though slightly GM Modified, LF353 harsh yet smooth, NE5532 a slight hint of water melon, AD OP271 mellow with a hint of raspberry ........... screw will somebody please hit me over the head with a hammer!!!!

<screaming>

Quote:



Why? In a circuit like this (opamp + output stage in its feedback loop) I'd expect the opamp to be the single most important factor on the sound quality...

I have the AD8620 on BrownDog in my Chiarra (as does London Luke). Very nice - mine's out on loan to a friend at the moment (spreading the Chiarra word), so can't currently do any opamp swaps for feelings on the differences. However, I liked it more than the 823, by a fair way.

Be careful - the standard power supply puts out +-15v, and I believe (it was certainly suggested to me) that the AD8620 will only take +-12v.

Quote:



Hi Richard,

I'll measure between R1 "3k3" and 0V to see what voltage is being supplied to the opamp. I've looked at the 8620 data sheet and the voltage range is +/-5V to +/-13V. I hope the voltage supplied to the opamp "isn't" 15V

The absolute maximum "stress rating" of the 8620 is 27.3V so, even if it was receiving 15V it wouldn't melt but I don't want to sail that close to the wind!!!

Mike.