[12796]

Maybe it sounds so good BECAUSE you have removed both sets of caps? Try the ad8065 in the same configuration

 

[PinkFloyd]

Quote:

Originally Posted by StevieDvd It's not a 3amp fuse is it?

No, It's a chrome plated safety pin

<joke>


Quote:

Originally Posted by StevieDvd Where do you measure it though?

First you arm yourself with a multimeter set to the 200mV range (200m DC)

Once suitably armed with said multimeter you probe between sleeve and ring (right channel) and sleeve and tip (left channel)..... just back from taking a couple of pics hope this makes it easier to follow:

Multimeter set on 200m setting (DC)

With amp turned on but no music playing probe between sleeve and ring (ground and right channel) as shown. The offset (if any) will be displayed on your multimeter. If there is DC then trim the right channel pot (using the screw on the pot) until it measures as close to 0.00mV as possible. It may take quite a lot of turns of the screw but you'll get it down to 0.00mV eventually.

Again.... With amp turned on but no music playing probe between sleeve and TIP (ground and left channel) as shown. The offset (if any) will be displayed on your multimeter. If there is DC then trim the left channel pot (using the screw on the pot) until it measures as close to 0.00mV as possible. It may take quite a lot of turns of the screw but you'll get it down to 0.00mV eventually.

IIRC I marked your two trimpots L & R Steve? so, you adjust the L trimpot to trim the left channel (whilst probing between sleeve and tip to measure the DC) and you adjust the R trimpot to trim the right channel (whilst probing between sleeve and ring to measure the DC)

I hope this makes sense, I'm not long out of bed and have a blistering headache but will add more to this tutorial later on if necessary.

Mike.

 

[PinkFloyd]

Quote:

Originally Posted by biovizier Maybe it sounds so good BECAUSE you have removed both sets of caps? Try the ad8065 in the same configuration

Been there done that last year but will go there again once I mount my 8065's Nick..... tried them in the MKl and really loved them but then, after prolonged listening, I (for some reason) deleted my 8065 rave post and wrote this:

[size=large]11-01-2004[/size]

[size=medium]"Further to my ravings on the AD-8065 I fear I was premature in extolling their sonic virtues. Prolonged listening to a wide variety of musical genres (lasting to 5am this morning ) revealed some kinks in the 8065's armoury which has made me decide to go back down the LM6171 route.......

With simple music such as a Jazz trio, electro, reggae etc. the AD8610 has no problems handling things and sounds pretty darned good..... it's only when you play a more complex piece of music that it falls by the wayside bigtime .......

Tchaikovsky's 1812 overture is a prime example, the opening sounding mellifluous and melodic just as it should do... so good so far... however, near the end of the piece things go seriously out of control big time.... instead of the usual climactic assortment of bangs and crashes, canons firing and pealing of bells my ears were presented with a mismash of congested rasping and clashing sounds..... I just couldn't make out any of the individual instruments it was a right old cacophony! seriously ear bleedingly harsh, splashy and trashy sounding.

Ad-8065 is the same across the board with any complex piece of music it just runs out of steam and instruments all run into each other and come across as one congealed, compressed mass instead of individual instruments each doing their own thing in their own space in the soundstage.

Pity as the AD-8065 sounds so good with very simple music

Oh well, it's back to the LM6171 for me and I've ordered some 470uF ALCAP output caps which should cover all bases and eventualities.. the 12uF I had been using were obviously not high enough capacitance so I can't wait to hear the WNA with LM6171 and 470uF ALCAPS

Will report back on the large ALCAP and LM6171 combo"[/size]

Things have certainly "progressed" since then (470uF ALCAPS "Cringe") Must try them again in the MKll, they really were a nice sounding chip in the MKl.

EDIT: The amp I tried the 8065's in was a bit of a disaster zone / Rice Krispie (snap crackle & pop) if truth be told so yeh, will definitely give them another whirl in in the "tidy" MKll

Disaster Zone:

 

[StevieDvd]

Quote:

Originally Posted by PinkFloyd No, It's a chrome plated safety pin <joke> First you arm yourself with a multimeter set to the 200mV range (200m DC) Once suitably armed with said multimeter you probe between sleeve and ring (right channel) and sleeve and tip (left channel)..... just back from taking a couple of pics hope this makes it easier to follow: ... I hope this makes sense, I'm not long out of bed and have a blistering headache but will add more to this tutorial later on if necessary. Mike.

Thanks that makes perfect sense, now I know what to do when I find out what you are using instead of the safety pin.

Steve

 

[Henry Morgan]

Is it time yet for Pinky to reveal the new champion device? I've not been up to speed lately with my WMA headphone amp due to other distractions, so I've got a lot of catching up to do. Long winter months ahead now etc.
Henry.

 

[Alick]

Quote:

Originally Posted by Hernry Morgan I've not been up to speed lately with my WMA headphone amp due to other distractions, so I've got a lot of catching up to do. Long winter months ahead now etc.

Me too Henry. I can't quite believe how long I've been away from this thread. However, summer has gone and, although I've been listening a lot (I replaced my Squeezebox with a Squeezebox2 and did away with my external DAC), it's time to lift the lid and do some modding again. I never did get round to doing the trimpot mod, so that's next.

Mike, ISTR that you reverted to the original bias current when you removed the output cap's. I'd like to do the same as introducing heatsinks has made things look like a dogs dinner as there really isn't the room for them given the spacing of the transistors on the board. Did you find that the increased bias current mod was less effective with the cap's out?

BTW, I see David has updated the catalogue and the Mk2 is now listed (at least I assume it's the Mk2).

 

[12796]

so what is the chip pinkie?

 

[StevieDvd]

Yes will mine need to be upgraded to the new superchip?

Steve

 

[raja]

Hi,

I remember there was interest in the super regulators at one point.

Here is a link for a possible upcoming purchase of pcb's,

The pcb's are very cheap, but parts can still cost around £20 or so, for this cost you should be able to stuff a couple of boards.

How the super reg's will work on the updated headamp is a bit of a mystery though, as the power supply is improved over the previous versions.

http://www.pinkfishmedia.net/forum/s...ad.php?t=15588



thanks
Raja

 

[12796]

Unfortunately I am banned from pink fish

 

[Jazper]

what's the bet it's a TL071?

 

[raja]

Quote:

Originally Posted by biovizier Unfortunately I am banned from pink fish

tut tut sonny, what've you been up to?



The thought of the opamp being the tl071 had crossed my mind too.


Thanks
Raja

 

[12796]

its a 741!

I had the temerity to suggest naim were poor VFM, linn make awful turntables and ATC can strip the paint off walls. Then I got abused by kiddies every time I posted - including the mods. Gave them a sound thrashing and got banned eventually. Mods then deleted all requests for my return.

Nick.

 

[PinkFloyd]

Jeez Geezers, it's not a "superchip" or some mysterious wonderchip It's the good old Burr Brown OPA228P.

I've got it running in both my amp and Steviedvd's MKl amp at the moment with no output caps, no input caps or other **** in the signal path..... It's by far "my" favourite in the WNA but that doesn't necessarily mean a lot as ears are as unique as fingerprints and we all hear things differently... some may love it, some may like it and others may despise it but It sure is worth giving it a try.

To be perfectly honest I'm sick and tired of that prima donna LM6171 and all the associated crap that's required to get it to work without oscillating or behaving badly.... output caps, input caps, trimpots etc.

I'm going back to bare bones where less is more and the OPA228P suits my ears down to the ground. I haven't posted before now because I wanted to be absolutely sure..... at the moment It's pretty much plug and play (without input / output caps) with zero DC offset (+0.01mV R 0.00mV L) and I'm sure even more could be squeezed out of it...... It likes a gain greater than "5" so It's probably a good idea to "up" the WNA's gain to 6 though it works perfectly well with the standard WNA gain of 4.3

Listening to Steviedvd's "Barebones" 228 MKl WNA right now (after spending the afternoon and evening faffing about with it) and Frank Sinatra sounds like he's in the same room with me (dunno if that's good or bad!) I'll leave you to comment on it Steve and if it doesn't suit your ears then I'll retrofit the LM6171, input caps, trimpots, 10M resistors et al.

You can also try the AD8065, OPA627 and many more chips Steve without the need for the signal strangling in / out caps.... They are direct drop in (plug and play) chips, try them all!

Mike.

Zippin' up my boots, goin' back to my roots, yeah,
To the place of my birth, back down to earth.

I've been standing in the rain,
Drenched and soaked with pain,
Tired of short time benefits
And being exposed to the elements.
I'm homeward bound, got my head turned around.

Zippin' up my boots, goin' back to my roots, yeah,
To the place of my birth, back down to earth.
Ain't talkin' 'bout no roots in the land,
Talkin' 'bout no roots in the man.
I feel my spirit gettin' old, it's time to recharge my soul.
I'm zippin' up my boots, goin' back to my roots, yeah,
To the place of my birth, back down to earth.

Zippin' up my boots, goin' back to my roots.
To the place of my birth, back down to earth.

 

[raja]

Quote:

Originally Posted by biovizier its a 741! I had the temerity to suggest naim were poor VFM, linn make awful turntables and ATC can strip the paint off walls. Then I got abused by kiddies every time I posted - including the mods. Gave them a sound thrashing and got banned eventually. Mods then deleted all requests for my return. Nick.

Oh well, I guess you live 'n' learn bro'.

I agree with pinkie, sometimes less is more. Sometimes when you complictae the signal path as little as possible it sounds best.