Clever idea with chip mount and PCB. If I see it correctly, the screw is not attached to the PCB and the chip leads are bent the other way. In a long run it may put too much stress on the leads. How about using plastic spacer between board and chip, so the screw will hold the board as well?
You may also try your amp without coupling caps, if DC offset is not too big. I did this in my second implementation and it works fine with max DC less than 100mV. I also tried 1.5k resistor from output to - rail. It seems that the sound is indeed cleaner, with the impression of a slower pace. Maybe a bit of magic is gone, so it's hard to decide if it's improvement or not.
I would, but I'm not sure what I'd be sacrificing... Coupling caps are used for blocking DC, right? So what happens when the DC isn't blocked? Can't be good on the speakers, right?Peter Daniel said:
I guess I'm asking why someone would or wouldn't be comfortable removing the coupling caps of an amplifier.
--Jordan
When DC isn't blocked, at certain level it will damage your speakers. But quite a few high end amps are not DC blocked (Aleph is one example). So it all depends on your source components and preamp, how much DC they produce.
Gainclone by itself generates no more than 20mV of DC at the output. If your preamp is AC coupled or produces very little DC offset, it is quite safe to omit DC blocking cap at amps input. I remember that on my first one, even when I was using BOZ with output caps, I still had around 300mV of DC offset. But in my current setup, DC is less than 100mV and usually around 40mV.
It is always best to check with your meter what values of DC you are dealing with. The advantage is, that you get rid of a sonic signature of the cap, and sometimes it is worth it.
If I built a clone for somebody, I always include a cap (BG, N type), just to be safe.
Gainclone by itself generates no more than 20mV of DC at the output. If your preamp is AC coupled or produces very little DC offset, it is quite safe to omit DC blocking cap at amps input. I remember that on my first one, even when I was using BOZ with output caps, I still had around 300mV of DC offset. But in my current setup, DC is less than 100mV and usually around 40mV.
It is always best to check with your meter what values of DC you are dealing with. The advantage is, that you get rid of a sonic signature of the cap, and sometimes it is worth it.
If I built a clone for somebody, I always include a cap (BG, N type), just to be safe.
Do you use 2.2-4.0 uF BG's ? Or larger 100 uF-220 uF ? I have heard that distortion is lower for larger electrolytics. But I don't know if this also applies to BG's.
Especially with my ERO MKT's I could really hear the signature of the cap, the mid get's a little bit harsh. And the bass slower. With the better quality cap (ERO MKC) I use now, the difference is not so apparant anymore...
Fedde
Especially with my ERO MKT's I could really hear the signature of the cap, the mid get's a little bit harsh. And the bass slower. With the better quality cap (ERO MKC) I use now, the difference is not so apparant anymore...
Fedde
Hi!
Well, I killed a midrange woofer in my left speaker while experimenting with GC due to a high DC offset (somewhere around 12 - 14 V)... Sadly this midrange woofer (Visaton) isn't available any longer... So now I have all my beautiful new DIY equipment but no classy speakers to use them with (- and no money right now to build new ones...)
But I have learned... now I always check DC offset before attachning any speakers to DIY stuff...
JordanG said:
Well, I killed a midrange woofer in my left speaker while experimenting with GC due to a high DC offset (somewhere around 12 - 14 V)... Sadly this midrange woofer (Visaton) isn't available any longer... So now I have all my beautiful new DIY equipment but no classy speakers to use them with (- and no money right now to build new ones...)
But I have learned... now I always check DC offset before attachning any speakers to DIY stuff...
protos said:
My plans have changed. I had an almost finished pair of Aleph 2 monoblocks, but I have since changed my mind and am using the 2 chassis for 1 - Aleph-X and 1 - Aleph 5. I have them almost done, but haven't gotten my power supply caps yet.
I have gotten sidetracked by other projects (mostly speakers).
--
Brian
I was doing some listening tests (with two other persons) on my two gainclones.
First thing I found out is that 1.5K resistor from output to - rail KILLS THE SOUND. This is not exaggeration, in my setup it was simply unnexceptable. I used 3W Panasonic. With the resistor in place the sound was dull, not open, uninvolving and simply boring.
Next thing I found out is that my acrylic clone, starting this thread, doesn't sound as good as the original aluminum body clone. It's just producing less magic. And it does not use coupling caps and is using supposedly better pot (Alps Black Beauty), yet in straight comparisons it is sounding less musical.
I built for it a PS with 2 EI core split bobbin transformers (200VA ea.), schottky diodes, Kimber 8TC cable and output voltage of 18V.
My original supply consisted of 400VA Plitron toroid, Motorola MUR soft recovery diodes, 8 strands of silver plated teflon insulated wire for umbilical cord, plus it was producing 24V output.
To my surprise, the second supply sounded better.
The guy who keeps my original gainclone is raving about it. He claims it is the best amp he ever had, it is better than any SS amp, better than tube amps and in his words, it would be really hard to improve on. He actually told me not to touch anything, because it's almost perfect. The only improvements we were concentrating on, were mechanical tuning with different spikes, supporting platforms and some other accessories. And everything made noticable change.
Some people commented that their GC don't have enough bass. This amp has all the bass you would ever need, with perfect gradation, punch, tightness and whatever else you might need.
Hearing this amp, fully broken in, was really eye opening. Sorry to brag about it so much, but i'm still under the impression of that listenning session. It is definitely worth to build, but proper choice of parts, layout, chassiss, PS and most other construction aspects are very important and perfect sound is not always guaranteed.
First thing I found out is that 1.5K resistor from output to - rail KILLS THE SOUND. This is not exaggeration, in my setup it was simply unnexceptable. I used 3W Panasonic. With the resistor in place the sound was dull, not open, uninvolving and simply boring.
Next thing I found out is that my acrylic clone, starting this thread, doesn't sound as good as the original aluminum body clone. It's just producing less magic. And it does not use coupling caps and is using supposedly better pot (Alps Black Beauty), yet in straight comparisons it is sounding less musical.
I built for it a PS with 2 EI core split bobbin transformers (200VA ea.), schottky diodes, Kimber 8TC cable and output voltage of 18V.
My original supply consisted of 400VA Plitron toroid, Motorola MUR soft recovery diodes, 8 strands of silver plated teflon insulated wire for umbilical cord, plus it was producing 24V output.
To my surprise, the second supply sounded better.
The guy who keeps my original gainclone is raving about it. He claims it is the best amp he ever had, it is better than any SS amp, better than tube amps and in his words, it would be really hard to improve on. He actually told me not to touch anything, because it's almost perfect. The only improvements we were concentrating on, were mechanical tuning with different spikes, supporting platforms and some other accessories. And everything made noticable change.
Some people commented that their GC don't have enough bass. This amp has all the bass you would ever need, with perfect gradation, punch, tightness and whatever else you might need.
Hearing this amp, fully broken in, was really eye opening. Sorry to brag about it so much, but i'm still under the impression of that listenning session. It is definitely worth to build, but proper choice of parts, layout, chassiss, PS and most other construction aspects are very important and perfect sound is not always guaranteed.
Banned
Joined 2002
Peter Daniel said:I was doing some listening tests (with two other persons) on my two gainclones.
First thing I found out is that 1.5K resistor from output to - rail KILLS THE SOUND. This is not exaggeration, in my setup it was simply unnexceptable. I used 3W Panasonic. With the resistor in place the sound was dull, not open, uninvolving and simply boring.
Next thing I found out is that my acrylic clone, starting this thread, doesn't sound as good as the original aluminum body clone. It's just producing less magic. And it does not use coupling caps and is using supposedly better pot (Alps Black Beauty), yet in straight comparisons it is sounding less musical.
I built for it a PS with 2 EI core split bobbin transformers (200VA ea.), schottky diodes, Kimber 8TC cable and output voltage of 18V.
My original supply consisted of 400VA Plitron toroid, Motorola MUR soft recovery diodes, 8 strands of silver plated teflon insulated wire for umbilical cord, plus it was producing 24V output.
To my surprise, the second supply sounded better.
The guy who keeps my original gainclone is raving about it. He claims it is the best amp he ever had, it is better than any SS amp, better than tube amps and in his words, it would be really hard to improve on. He actually told me not to touch anything, because it's almost perfect. The only improvements we were concentrating on, were mechanical tuning with different spikes, supporting platforms and some other accessories. And everything made noticable change.
Some people commented that their GC don't have enough bass. This amp has all the bass you would ever need, with perfect gradation, punch, tightness and whatever else you might need.
Hearing this amp, fully broken in, was really eye opening. Sorry to brag about it so much, but i'm still under the impression of that listenning session. It is definitely worth to build, but proper choice of parts, layout, chassiss, PS and most other construction aspects are very important and perfect sound is not always guaranteed.
Then post some pictures of your finnished product. with coer off too. and in it's posision now. ie where is it laying.
Banned
Joined 2002
RAYSIMMONS said:
I'm using Rikken resistors, BG N 4.7u coupling cap, some odd Alps pots paralleled for mono operation (50K final resistance) and 2 x 1000u/50V Standard Polarised BG PS caps. Since the other amp used different pot and no coupling caps, I might suspect that it's BG coupling cap in combination with the pot add some special coloration to the overall sound.
I also think that the chassiss and true mono construction do something to the sonics as well. I might consider myself lucky, that it came out like this on a first try.
Schematic was posted in this thread as simplified, inverted Gainclone.
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