[Karlosak]

Hi,
want to build META (per Tangent's tutorial) and I would like it to suit my HD-600 the best.

Any suggestions about picking the parts (e.g. op-amp, gain, number of buffers, etc.)?:

I thought about this:
AD8620 op-amp
ALPS RK27112 pot, 50K
EL2001CN (or EL2002CN does better?)
- how much of them is reasonable?
PANASONIC FC cap 35V 1000uF (C2/C3)
Wima MKS-2 6.8µF/50V (C4)
Cascode set for biasing into class A (R10 value?)
All resistors from Tangent's schematic
- that is gain about 10 (is that OK?)
no crossfeed
battery powered (18V), current draw isn't issue - it has really big capacity (2500 mAh

)

sorry for my dummy questions - I'm quite new to the DIY - built a CMOY but now want to give the META a try!

So if you know any hints/tweaks for META to make my HD-600 shine, please tell me

 

[Arzela]

In my opinion, the 600's and the ad8620
are a bad combo. They'll sound bright.
Dare I say shrill?.

An OPA627, I think, is a better
mate for the 600's.

The 600's are relatively high impedance
and need little current.
Thus, 2001's would be fine. I imagine stacking
them would have no appreciable effect.
The 2002's do have lower distortion though....


With the 627, class A does help out a lot.
I think the ad chip already runs in class A.

just my 2 cents

 

[Karlosak]

Really?
I went through some older posts and many folks there are saying that ad8620 does great job with HD-600.

I´m still hesitating between AD8620, AD843 and OPA627, although I'll probably pick the first one.

Any other sugestions?

 

[[so]hai(R)]

i prefered AD8620 with HD600 while OPA627/637 with Grado....

reason? look at the frequency response of those cans and u'll find that grado cans is brighter than HD600... and AD8620 is a "bright" opamp, so u get better highs with AD8620 combo with HD600...

I've tried both of them and i prefered AD8620 although OPA627 is also very good....

just my £0.02....

 

[eric343]

I love the AD8620.

If you want an 'ultimate META42' configuration, look into the modifications kfaiman did to a META I made him (before you ask, I'm no longer making them). EL2009, Black Gates, etc... probably cost him a bundle and the EL2009s are quite rare indeed.

 

[Karlosak]

Thanks for income.
I think that my favourite is clear now - AD8620.

P.S.: Can´t wait for the METAparts to arrive...
Waiting can be sometimes so unbearable

 

[fiddler]

I have a modded Corda with OPA627, and a META42 with AD8620. Yes, they are different amp designs, but I the opamp seems to affect largely the sound of both these amps.

AD8620- More treble detail and "air", more texture.

OPA627- Stronger bass, but IMO it's too much. "Smoother", but at the expense of details. Just too damn dark to use with HD600.

I greatly preferred the META42/AD8620 over the Corda/OPA627 driving HD600.

 

[puppyslugg]

I think the ad843 offers the best(most) qualities of both the opa627 and ad8620. Though I ended up using the ad843 in my Corda, I could very easily have 'lived' with the ad8620.

 

[joe_cool]

I'm kinda alone in this, but I definitely prefer the AD825 for use in audio. The Elantec 2002 does sound better than the 2001. I have a META42 with stacked 2002s and it's quite good with a regulated 24 volt power supply. For HD600s you don't need to stack the buffers, but I don't know where to buy the 2002s as Tangent is sold out. Gain of 11 is about right for 580s/600s.

 

[Karlosak]

Yes the EL2002 are difficult to find.
The only source I know about is RS-components but they're quite expensive (4.6 pounds in Europe - that is about $7

) so I think I'll stick to EL2001 from Tangent.

 

[puppyslugg]

Quote:

Originally posted by Karlosak Yes the EL2002 are difficult to find. The only source I know about is RS-components but they're quite expensive (4.6 pounds in Europe - that is about $7 ) so I think I'll stick to EL2001 from Tangent.

If RS still has the el2008/9's available, I would highly recommend looking into those. Though not recommended for portable amps