Something else I noticed, the soundstage widens when I crank up the volume instead of being in yer face like the minimized one.
The main thing though is the vocals, beautiful😀
Come on guys, Its about time more people tried these Clones
😉
The main thing though is the vocals, beautiful😀
Come on guys, Its about time more people tried these Clones
😉
Re: Weekend update
Using 78/7915 is more healthy for the OPA627s as +/- 18 V is their *absolute* maximum supply voltage. Using a diode per side ( in series ) after the 78/7918 to drop voltage with 0.6 V works just as good. Always check/measure 78/79Lxx as they deviate from the specified voltage more than they should with some brands. I would not operate the opamps for a longer time at ( or just above ) their absolute maximum ratings to avoid my woofers having severe headaches 😉
When taking the bandwidth of OPA627 into consideration it is very wise to use a RC filter at its input. A 1k5 series resistor followed by 1 nF styro/MKP to ground ( all this between the 100 k resistor and the chip ) normally will do. I always use input filters in amps, the need for them is only becoming bigger with todays RF pollution ( GSM etc. ).
carlosfm said:Version 2.0 of the BIGC schematic, with some "minor" 😱 bugs corrected.😀
That crap ExpressSCH has wrong pinouts on these regulators.😱
Bob, the schematic you made is fine now😎 , and has better image resolution than mine.
I have to resize this to post here, and it looses resolution.
Here it is.
Using 78/7915 is more healthy for the OPA627s as +/- 18 V is their *absolute* maximum supply voltage. Using a diode per side ( in series ) after the 78/7918 to drop voltage with 0.6 V works just as good. Always check/measure 78/79Lxx as they deviate from the specified voltage more than they should with some brands. I would not operate the opamps for a longer time at ( or just above ) their absolute maximum ratings to avoid my woofers having severe headaches 😉
When taking the bandwidth of OPA627 into consideration it is very wise to use a RC filter at its input. A 1k5 series resistor followed by 1 nF styro/MKP to ground ( all this between the 100 k resistor and the chip ) normally will do. I always use input filters in amps, the need for them is only becoming bigger with todays RF pollution ( GSM etc. ).
Clones?
I don't think we can still call this a Gainclone...
Well, call it if you like.
This is evolution.
Actually I've put a name on my little amp: mini-Krell.😀
t. said:
I don't think we can still call this a Gainclone...
Well, call it if you like.
This is evolution.
Actually I've put a name on my little amp: mini-Krell.😀
Re: Re: Weekend update
Never had problems with that.
Anyway, most of the times the voltage you get out of these regs is a little below 18v, sometimes 17.5.
But, of course, the 7815/7915 will be fine too.
jean-paul said:
Never had problems with that.
Anyway, most of the times the voltage you get out of these regs is a little below 18v, sometimes 17.5.
But, of course, the 7815/7915 will be fine too.
Nuuk, here you go:
http://www.diyaudio.com/forums/showthread.php?s=&postid=424115&highlight=#post424115
Hey Leo! Good to see you here! Also good to read you have finished the amp. how does it compare to you-know-what.........? 😉
http://www.diyaudio.com/forums/showthread.php?s=&postid=424115&highlight=#post424115
Hey Leo! Good to see you here! Also good to read you have finished the amp. how does it compare to you-know-what.........? 😉
NealG said:
Hi Neal,
Well it sounds alot different😉 , whats your honest opinion?
I'm interested in listening to your tube pre with the regulated Clone/thingy, we should have another meet up at Richards, he's also wanting to know how they sound.
The J-fet buffer sounds very good and matches my cdp and speakers very well
Re: Clones?
you can use the words "mini" and "krell" in proximity?! I never knew. 😉
waiting for parts is no fun at all.
C
you can use the words "mini" and "krell" in proximity?! I never knew. 😉
waiting for parts is no fun at all.
C
Thanks Neal. I found the link but it seems as though 'the real thing' is preferred to a software version!
And I've been reading this in the hope that I will one day own one! 😉
I've just placed an order with Farnell so I should have my replacement LM338 here on Tuesday.
Mini Krell!!!!!! Sounds like some sort of fast sea-food. 😉 Can't we do better than that? What about RCA? Or BARCA?
Hi Nuuk,
I also had a few problems with my LM338 to start with, I always got full voltage on the output no matter what adjustment resistor I used.
I took them out and measured them, they measured different to my unused pair so I stuck them in instead, it now works fine.
Good luck with the new ones, it will be worth the hassle😉
Which buffer section are you using, is it still the valve one?
Leo
I also had a few problems with my LM338 to start with, I always got full voltage on the output no matter what adjustment resistor I used.
I took them out and measured them, they measured different to my unused pair so I stuck them in instead, it now works fine.
Good luck with the new ones, it will be worth the hassle😉
Which buffer section are you using, is it still the valve one?
Leo
No the OPA627 but with a few changes. Actually I have included a socket to try a few different opamps.
The second regulation stage of the PSU is now on the same PCB as the buffer circuit. (Both stages use 337/317 regs)
I am going to try a bit of gain with it as Pedja suggested it could sound a bit better than at unity gain.
I have also included the option to run it in class A mode.
Full details (including circuits) when I have it up and running! 😉
Nuuk said:
Nice one Nick, sounds interesting, your going to be busy then over the week🙂
Just replied over at Gainclone forum
Nuuk said:
I always use sockets.
Last week I was regulating my LM4780 GC.😎
It has an OPA2132 as an input buffer.
After finishing the work, I connected this amp to my main system.
😎 , as expected.😀
As I've made an adapter to test the (much raved) AD8620, it was time to try it.
OPA2132, back in, please!😀
Re: Re: Re: Weekend update
using a 7815/7915 is like getting your car's oil changed and putting back on the dirty old oil filtercarlosfm said:
carlosfm said:
I always use sockets.
Last week I was regulating my LM4780 GC.😎
It has an OPA2132 as an input buffer.
After finishing the work, I connected this amp to my main system.
😎 , as expected.😀
As I've made an adapter to test the (much raved) AD8620, it was time to try it.
OPA2132, back in, please!😀
I tried the 8620 twice in a Sony SACD player. It was bright both times. It seems to need a lot of decoupling to remain stable. And it seems to work best at 12 volts or less.
Normally I use the 2604. But just becuase there a tube of them in my parts box. The 2132 is just as good, maybe better in some applications.
Rereading your post, did you hit it with 18 volts?
George
You are more than welcome carlosfm. 😎
I'm very pleased with your contribution on this forum.🙂
What you think about this:
You are ok to include this for Rev_4 or to stay with Rev_3 at the moment?😎
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