In that case you need preamp. The beauty of Gainclone is enough gain and when the volume is at the amp, no neccessity of using preamp. My least efficient speakers are around 91dB and I usually play the amp at 7/8 of volume setting. With 93 dB or more it's hard to play it at full volume.
87 dB though isn't enough for realistic sound levels. What about Pass preamps or anything from Borberly? There was a thread started by Dorkus, where different preamp circuits were discussed: http://www.diyaudio.com/forums/showthread.php?s=&threadid=3625&highlight=preamp
87 dB though isn't enough for realistic sound levels. What about Pass preamps or anything from Borberly? There was a thread started by Dorkus, where different preamp circuits were discussed: http://www.diyaudio.com/forums/showthread.php?s=&threadid=3625&highlight=preamp
Better load for gainclone?
I've just about decided on some drivers (PHL)
which are available in either nominal 8 or 16 ohms.
Re choice is either 6.1 or 12.1(±10%).
http://www.e-speakers.com/PDF's/PHL1240.pdf
To be driven by a gainclone, maybe 3886 or the TDA1294
for a gainclone should I get the 6.1 or 12.1 ohm load?
TIA, Richard
I've just about decided on some drivers (PHL)
which are available in either nominal 8 or 16 ohms. Re choice is either 6.1 or 12.1(±10%).
http://www.e-speakers.com/PDF's/PHL1240.pdf
To be driven by a gainclone, maybe 3886 or the TDA1294
for a gainclone should I get the 6.1 or 12.1 ohm load?
TIA, Richard
bias into class A?
Amongst a number of others, Thijs some time back suggested forcing bias into class A.
A (class A enthusiast) friend suggested to bias into class A, with Plenty of heatsinking (sure $+) "like an Aleph".
Bias adjustment would be an option.
Anyone can give a quick summary of the sonic benefit?
Amongst a number of others, Thijs some time back suggested forcing bias into class A.
A (class A enthusiast) friend suggested to bias into class A, with Plenty of heatsinking (sure $+) "like an Aleph".
Bias adjustment would be an option.
Anyone can give a quick summary of the sonic benefit?
Banned
Joined 2002
Peter Daniel said:I got 1230 and was planning to use them in parallel with Raven 2 in MTM config. If the impedance is pretty steady and doesn't go down too much I would go with 6ohm and gainclone. Maybe it's time to ask Andre again, he seems to be pretty knowledgable.
Your going to build another pair of speakers. Can i see. your idea's.
i was thinking about this. http://www.creativesound.ca/details.php?model=CRITERION
I hope I will built some new speakers this summer, especially if I have enough drivers for 5 sets at least. Whenever I come with something new, I post it here. The drivers I mentioned before, were bought 4 years ago and are still on a shelf. I bought some Triangle drivers from the guy you recommend me on E-bay. He had some good deals.
Banned
Joined 2002
Hi rick57,
I hope you were not talking about me! I have made some remarks about the popular biasing mod of the gainclone (a 1K5 or so resistor to V-).
To summarize:
The effect of resistor is a DEcrease of bias current in one half of the ouput transistors, not an increase (simmulated the whole thing in spice)
The amount of current that is targeted for is not high enough anyway (about 20mA).
For some increare of Class A ouput from a gainclone I suggest a 4chip parrallell brigde configuration.
greetings,
Thijs
I hope you were not talking about me! I have made some remarks about the popular biasing mod of the gainclone (a 1K5 or so resistor to V-).
To summarize:
The effect of resistor is a DEcrease of bias current in one half of the ouput transistors, not an increase (simmulated the whole thing in spice)
The amount of current that is targeted for is not high enough anyway (about 20mA).
For some increare of Class A ouput from a gainclone I suggest a 4chip parrallell brigde configuration.
greetings,
Thijs
tschrama said:
Personally I've found that unless you're going to go full-blown class A such that you're never going to drop out of it under typical conditions, it's best to keep the biasing as close to class B as possible.
Some seem to prefer the increased distortion brought on by a marginal increase in class A biasing, but it didn't set so well with me.
I don't always shoot for the lowest possible distortion and there have been many instances where I've subjectively preferred a bit less linearity. But this wasn't one of them.
se
Re: Re: Preamp for gainclone
Technically there's no reason you can't get all your voltage gain from the chip itself (and of course higher voltage gain means less negative feedback). And while it makes for a much simpler result, some still prefer to use a separate preamp/amp combination. Go figure.
se
Mad_K said:Why don't you just increase the gain a little? Just put in a bigger resistor in the place of the 220K? say 440K=33dB
Technically there's no reason you can't get all your voltage gain from the chip itself (and of course higher voltage gain means less negative feedback). And while it makes for a much simpler result, some still prefer to use a separate preamp/amp combination. Go figure.
se
Here's a little stand I made today for my Gainclone. It is made out of two slabs of 1" acrylic with 1/8" thick piece of blown rubber in between (stuff used in shoes and sleepping pads). The size is 12" x 8.5". I just used longer rods between the spikes and top nuts and here we are, a nice little support for an amp.
To say that it improved sonics dramatically, wouldn't be exaggeration. I came across that kind of platform by accident, a friend of mine asked me to do it for his portable Sony CD player. I did a small stand and before giving it to him I tried it with my amp. I noticed it's good, so today I made a bigger version.
There is much bigger depth, and the sound is cleaner and much more solid now. I usually don't listen to classical and jazz, but with this setup I really enjoy that type of music. This is highly recommended project and the cost is around $40 if you know where to shop
To say that it improved sonics dramatically, wouldn't be exaggeration. I came across that kind of platform by accident, a friend of mine asked me to do it for his portable Sony CD player. I did a small stand and before giving it to him I tried it with my amp. I noticed it's good, so today I made a bigger version.
There is much bigger depth, and the sound is cleaner and much more solid now. I usually don't listen to classical and jazz, but with this setup I really enjoy that type of music. This is highly recommended project and the cost is around $40 if you know where to shop
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Bricolo said:
I've heard people (amp chip diy) saying that they think the amp seems more dynamic etc with more gain.
I also seem to recall someone on this board saying that you loose bandwith as you up the gain, -> could someone more learned please comment on this?
I'm in the process of building a bridged OPA549 based amp right now, and I'm using a gain of 11x (21dB) per amp for a total of 22x (27dB).
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