hifive said:I've changed my Naim CD5 OPA 604 to OPA 627 and the improvements was good. But the only issue is in the vocal "ssss" too sharp. How should I rectify that...
Thanks
You can try decoupling from V+ to V- with npo 0.1 u ceramic and or decoupling to 0 rail. I personally don't like the dry character of the 627 and prefer class A bias on AD825 or heavilly dceoupled LM6171.
You should not always believe what you read about the 627
Re: Re: OPA604 to OPA627..some problems
With you there, the AD825 has killer transients and powerful tight bass, yet remains smooth as silk because it runs stinking hot in a lot of Class A, wish they made small SMD heatsinks for these. they really need them.
Cheers George
fmak said:
You can try decoupling from V+ to V- with npo 0.1 u ceramic and or decoupling to 0 rail. I personally don't like the dry character of the 627 and prefer class A bias on AD825 or heavilly dceoupled LM6171.
You should not always believe what you read about the 627
With you there, the AD825 has killer transients and powerful tight bass, yet remains smooth as silk because it runs stinking hot in a lot of Class A, wish they made small SMD heatsinks for these. they really need them.
Cheers George
Re: Re: Re: OPA604 to OPA627..some problems
How did you bias the AD825 to class A ??
For heatsinks, use u-shaped alloy channel available from hardware shops epoxyed to the chip. It overlaps a little but you can still solder. Brass channel is also available from model shops.
Andy
georgehifi said:
With you there, the AD825 has killer transients and powerful tight bass, yet remains smooth as silk because it runs stinking hot in a lot of Class A, wish they made small SMD heatsinks for these. they really need them.
Cheers George
How did you bias the AD825 to class A ??
For heatsinks, use u-shaped alloy channel available from hardware shops epoxyed to the chip. It overlaps a little but you can still solder. Brass channel is also available from model shops.
Andy
Re: Re: Re: Re: OPA604 to OPA627..some problems
Running at -15 +15 they run quite hot to the touch, (and no, they're not oscillating) to the point of wanting to cool them with a heat sink. OPA134,OPA2134 & OPA4134's SMD's, run this hot and also sound great, but the AD825's have better slam.
Cheers George
poynton said:
How did you bias the AD825 to class A ??
For heatsinks, use u-shaped alloy channel available from hardware shops epoxyed to the chip. It overlaps a little but you can still solder. Brass channel is also available from model shops.
Andy
Running at -15 +15 they run quite hot to the touch, (and no, they're not oscillating) to the point of wanting to cool them with a heat sink. OPA134,OPA2134 & OPA4134's SMD's, run this hot and also sound great, but the AD825's have better slam.
Cheers George
Cooler Master have a small self adhesive heatsink that fits well on DIP-8 opamp.
http://www.coolermaster.com/index.p...-P01&other_title=SAC-P01Little Chipset Cooler
http://www.coolermaster.com/index.p...-P01&other_title=SAC-P01Little Chipset Cooler
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banana said:Cooler Master have a small self adhesive heatsink that fits well on DIP-8 opamp.
http://www.coolermaster.com/index.p...-P01&other_title=SAC-P01Little Chipset Cooler
Yeah, but wot's needed is one for SMD size chips, 2 banger and 4 banger.
Cheers George
hifive said:
I'm getting 637BP next week!
Be careful !!!
Read the application notes !!!
Not unity gain stable !!
Andy
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