Hi Dan
Here's a couple of responses
I find this rather interesting purely because I have a 300D, which has a cascade front end, and I can set the bias in less than 15 minutes. So, this must be a very worth while mod.
Have a read on Greg's site. The mod looks like it is quite simple to implement. There appears to be one requirement and that is that the Source output impedance must be EQ or LT (=<) 800ohms.
ciao
Here's a couple of responses
I find this rather interesting purely because I have a 300D, which has a cascade front end, and I can set the bias in less than 15 minutes. So, this must be a very worth while mod.
Have a read on Greg's site. The mod looks like it is quite simple to implement. There appears to be one requirement and that is that the Source output impedance must be EQ or LT (=<) 800ohms.
ciao
Some comments of mine there, the snakeoil one. Just like to stick my oar and say that anyone with Greg's amp with a Zener mod should do the new tweak.
I didn't really believe this tweak would improve such a clear amp, I felt that we had to be in the land of diminishing returns with this but I was absolutely delighted.
I am not sure of the reasons but one major side affect of this mode for me was that the bias stability is significantly improved and setting the bias was a doodle.
Iain
I didn't really believe this tweak would improve such a clear amp, I felt that we had to be in the land of diminishing returns with this but I was absolutely delighted.
I am not sure of the reasons but one major side affect of this mode for me was that the bias stability is significantly improved and setting the bias was a doodle.
Iain
Hi all
As Mike has posted ... the posts suggest that the mod can only be used if your PreAmp, ie. source, is NOT greater than 800ohms output impedance. Greg, has posted that it is a synergy of components
You find all the details here ... “Simple New Tweak for GB150D” … http://ska-audio.com/Forum/YaBB.pl?num=1197570631/0
Have a look and let us know what you think?
ciao
As Mike has posted ... the posts suggest that the mod can only be used if your PreAmp, ie. source, is NOT greater than 800ohms output impedance. Greg, has posted that it is a synergy of components
You find all the details here ... “Simple New Tweak for GB150D” … http://ska-audio.com/Forum/YaBB.pl?num=1197570631/0
Have a look and let us know what you think?
ciao
Good points all! No Kle I don't mind at all, well posted
Impedance wise I use the SKpre so this was a nobrainer for me.
Best policy for any GB150 owners with other systems is to ask Greg, he is always helpful.
Worth noting that he is obviously busy with tweaks at the moment as he has just posted up an updated earthing scheme for a 2 channel GB150 so any GB150 owners around should probably take a look over at Greg's place.
Iain
Impedance wise I use the SKpre so this was a nobrainer for me.
Best policy for any GB150 owners with other systems is to ask Greg, he is always helpful.
Worth noting that he is obviously busy with tweaks at the moment as he has just posted up an updated earthing scheme for a 2 channel GB150 so any GB150 owners around should probably take a look over at Greg's place.
Iain
Well, I am a slow builder but 1 year later my Stereo 300Ds are pretty near finished. I spent a bit of time playing one channel today at moderate levels and man does it ever sound nice. I don't consider myself an audiophile but I can say with full confidence that this is the best sounding amp I have ever heard. I heard detail today that I never even knew existed. My system is not complete yet... and it will only get better as I put all the pieces together so I am quite excited... I will post a detailed review of this amp after my system is complete... Expect raving reviews.
Ryan
Ryan
Guys,
Greg has implemented a simple mod to his already GIANT KILLING, yet SIMPLE to build GB150.
With the mod, the noise floor is DEFINITELY MUCH LOWER and an already great amp sounds MUCH BETTER. You have to hear this diy amp!
I have said on previous posts that much of the emotional detail of music lives below the noise floor and this mod has allowed much more of that detail to come through. Even bass sounds tighter and the unmodded channel has a bass bloat/warmth which I never realised was there!
I sat till late listening to familiar CD's and for the first time in a long while, I was hearing new and really engaging music, details emerged that I'd never detected before and timing info popped into focus to ceate an even better impression of the overall performance. Acoustic guitar took on an amazing presence! As a bass guitar fan, it was wonderful to hear new details on lines I thought I was very familiar with.
Even just placing my ear right next to the tweeter I heard a substantial reduction in the low level hiss associated with the system.
I'm really impressed with the SKA150, especially with this mod. It is an amazing amp and, with the mod in place, matches for me the leap in enjoyment of music I experienced in using light dependant diodes for volume control.
FWIW, the rest of the system is:
1. Theta Data III drive, Wydeye balanced digital cable (which is marginally better than the Madrigal Fat boy)
2. Theta Gen Va DAC (highly modified with ultra low noise ALW (Andy Weekes) power supplies, parallel PCM63K's and extensive digital power supply/clock mods), Van den Hul the Second Balanced cable.
3. Carlosfm's implementation of the AD815. Replacing my old pre (627 with BUF634) with the AD815 was one of the best upgrades I've had in my system.
4. The balanced to single end converters used in the pre are THAT1200, the best I've heard and far outperforming any competitors (SSM, Analog, etc). The THAT1200 was created in collaboration with Jensen.
5. The volume pot in the pre is based on the Lightspeed Preamp, and uses light depedant resistors. A major leap forward in transparency!
6. Modified Royd Doublet speakers (new 30kg bases added, 5 9's silver internal wiring).
7. Speaker cable is a solid core, 28 gauge diy design
Ryan
Back to top
Greg has implemented a simple mod to his already GIANT KILLING, yet SIMPLE to build GB150.
With the mod, the noise floor is DEFINITELY MUCH LOWER and an already great amp sounds MUCH BETTER. You have to hear this diy amp!
I have said on previous posts that much of the emotional detail of music lives below the noise floor and this mod has allowed much more of that detail to come through. Even bass sounds tighter and the unmodded channel has a bass bloat/warmth which I never realised was there!
I sat till late listening to familiar CD's and for the first time in a long while, I was hearing new and really engaging music, details emerged that I'd never detected before and timing info popped into focus to ceate an even better impression of the overall performance. Acoustic guitar took on an amazing presence! As a bass guitar fan, it was wonderful to hear new details on lines I thought I was very familiar with.
Even just placing my ear right next to the tweeter I heard a substantial reduction in the low level hiss associated with the system.
I'm really impressed with the SKA150, especially with this mod. It is an amazing amp and, with the mod in place, matches for me the leap in enjoyment of music I experienced in using light dependant diodes for volume control.
FWIW, the rest of the system is:
1. Theta Data III drive, Wydeye balanced digital cable (which is marginally better than the Madrigal Fat boy)
2. Theta Gen Va DAC (highly modified with ultra low noise ALW (Andy Weekes) power supplies, parallel PCM63K's and extensive digital power supply/clock mods), Van den Hul the Second Balanced cable.
3. Carlosfm's implementation of the AD815. Replacing my old pre (627 with BUF634) with the AD815 was one of the best upgrades I've had in my system.
4. The balanced to single end converters used in the pre are THAT1200, the best I've heard and far outperforming any competitors (SSM, Analog, etc). The THAT1200 was created in collaboration with Jensen.
5. The volume pot in the pre is based on the Lightspeed Preamp, and uses light depedant resistors. A major leap forward in transparency!
6. Modified Royd Doublet speakers (new 30kg bases added, 5 9's silver internal wiring).
7. Speaker cable is a solid core, 28 gauge diy design
Ryan
Back to top
Hi KLE,
I have used the following in my system:
"Excalibur", a dual LM3886 based amp; This was the most recent
A LM3886 based amp
A LM3875 based amp, implemented with a ramge of mods, tweaks etc
Electrocompaniet (I forget the model details)
Mark Levinson monoblocks (I forget the details)
A diy tube based EL34
NAIM NAP 140; this was the first amp.
For me, Greg's amp has been a revelation in terms of transparency, openess, detail and finesse. Given that it is a reasonably straight forward DIY effort and at the price, it is easy to call this the best amp I have heard to date!
I have used the following in my system:
"Excalibur", a dual LM3886 based amp; This was the most recent
A LM3886 based amp
A LM3875 based amp, implemented with a ramge of mods, tweaks etc
Electrocompaniet (I forget the model details)
Mark Levinson monoblocks (I forget the details)
A diy tube based EL34
NAIM NAP 140; this was the first amp.
For me, Greg's amp has been a revelation in terms of transparency, openess, detail and finesse. Given that it is a reasonably straight forward DIY effort and at the price, it is easy to call this the best amp I have heard to date!
http://www.ska-audio.com/Forum/YaBB.pl
This is the forum - click on the banner at the top to get to the main site.
This is the forum - click on the banner at the top to get to the main site.
In my my audio universe it is not possible for an amp with a high noise floor to be more musical than an amp with a low noise floor.
Dr. H more or less already said as much.
a possible exception to this may be a situation where a noisy amp is masking the nasty details of a poor source but that is not really much of a recommendation for the source or the amp.
another possible exception may be mains hum. I have not noticed that this detracts from musicality - though I can understand that some may find it annoying in itself.
If all other measures have been taken to reduce noise in these SKA amps including a good low noise power supply then another thing to do is to change the feedback & gain resistors to high quality types. I recently fitted caddock TF020's and it made a very satisfying difference. If you have an electrolytic cap in the feedback circuit the effects of this mod might be less apparent but I would guess that they will still be noticable
mike
Dr. H more or less already said as much.
a possible exception to this may be a situation where a noisy amp is masking the nasty details of a poor source but that is not really much of a recommendation for the source or the amp.
another possible exception may be mains hum. I have not noticed that this detracts from musicality - though I can understand that some may find it annoying in itself.
If all other measures have been taken to reduce noise in these SKA amps including a good low noise power supply then another thing to do is to change the feedback & gain resistors to high quality types. I recently fitted caddock TF020's and it made a very satisfying difference. If you have an electrolytic cap in the feedback circuit the effects of this mod might be less apparent but I would guess that they will still be noticable
mike
Chaps, I've ordered up the parts for the mod as I was a little short. I will post my impressions when I have done it next week but sounds like I have something to look forward to.
Ryan does your GB150 have any other mods or is it as supplied but with the new mod? I am interested in playing around with other components at some point. Want to hear the affect of the new tweak first of course.
Iain
Ryan does your GB150 have any other mods or is it as supplied but with the new mod? I am interested in playing around with other components at some point. Want to hear the affect of the new tweak first of course.
Iain
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