Re: Bridge over trouble balance...
While it's balanced, it's not differential. In other words, that circuit would not reject common-mode noise which is the raison d'etre of balanced interfaces. Any common-mode noise on the line would be amplified and passed on to the loudspeaker.
Edit: Another thing worth noting is that when you bridge, each amp will need to supply twice the amount of current it would otherwise have to supply. And depending on the internal current limiting of the device, you may not end up with any more power in the end.
se
CheffDeGaar said:Apart from this, I've had a little idea for combining balanced input and more power... As bridging means having two signals of opposite phases, why not trying to use both signals of a balanced line to drive two amps, and connect the speaker between the two outputs. I've attached a little drawing of the idea. Is it worth testing ? Feel free to flame or praise. Notice that I didn't mentionned the polarities of inputs and outputs, since I don't know the answer to my first question
Cheers,
While it's balanced, it's not differential. In other words, that circuit would not reject common-mode noise which is the raison d'etre of balanced interfaces. Any common-mode noise on the line would be amplified and passed on to the loudspeaker.
Edit: Another thing worth noting is that when you bridge, each amp will need to supply twice the amount of current it would otherwise have to supply. And depending on the internal current limiting of the device, you may not end up with any more power in the end.
se
Now, if your manliness is offended by the typical girly-man Gainclones and you'd like to build a Gainclone with some real balls, try one of these puppies:
<center>
<img src="http://eportal.apexmicrotech.com/mainsite/products/pages/opimages/pa03.jpg">
</center>
It'll take up to +/- 75 volt supplies and dump up to 30 amps peak into the load. And it's priced at a manly $525 a pop.
se
<center>
<img src="http://eportal.apexmicrotech.com/mainsite/products/pages/opimages/pa03.jpg">
</center>
It'll take up to +/- 75 volt supplies and dump up to 30 amps peak into the load. And it's priced at a manly $525 a pop.
se
Inverting?
Hi Peter,
can you display input and output on your Scopemeter simultaneously? If not how do you know that they are not inverted? I notice that you have your scope set up for positive edge trigger. In this case the scope will show the upslope of the signal at the left hand side of the screen and hence will move an inverted sine by 180 degrees.
You might want to try triggering your scope off the input signal whilst measuring the output signal ( if your scope allows this ). Alternatively use a signal which cannot be confused if it is inverted e.g. a ramp.
James
Hi Peter,
can you display input and output on your Scopemeter simultaneously? If not how do you know that they are not inverted? I notice that you have your scope set up for positive edge trigger. In this case the scope will show the upslope of the signal at the left hand side of the screen and hence will move an inverted sine by 180 degrees.
You might want to try triggering your scope off the input signal whilst measuring the output signal ( if your scope allows this ). Alternatively use a signal which cannot be confused if it is inverted e.g. a ramp.
James
James,
That's a very good point. Since I'm not using the scope that much, I've never thought about it.
Of course the best way is to use both channels and see both waves simultaneously. My mistake. I was rather surprised seeing the same wave pattern on both input and output, but thought that scope would not lie.
Thanks for clarification.
That's a very good point. Since I'm not using the scope that much, I've never thought about it.
Of course the best way is to use both channels and see both waves simultaneously. My mistake. I was rather surprised seeing the same wave pattern on both input and output, but thought that scope would not lie.
Thanks for clarification.
Peter Daniel said:
Awwwwwwwww. Thanks, Peter
Haven't used the PA-03. Just don't have any need for that kind of power.
I've just used the PA-02 and PA-16, the PA-16 being the same as the PA-02 but in a power SIP package rather than the TO-3 type package of the PA-02.
In my experience, I've found them to be much better than the monolithics I've tried which I first started playing around with back in '90-'91. I was surprised to find the monolithics didn't sound quite as bad as the conventional wisdom at the time would lead one to believe.
But when I put them up against the first hybrid (the National LH-0101) there was no going back for me. Since then I've gone through the LH-0101, the Apex PA-02 and then a few years ago switched over to the PA-16.
And they've come down in price. I paid a little over $90 for my current PA-16s but now they're down in the $60 range. Considerably more than you'll pay for the monolithics, but even at $90 a pop I think they're worth it.
se
Re: Turn-on/turn-off DC transient
I use gainclones in my multiamped system even on horn tweeters without facing any problem. It is over 100dB efficient system and I dont have any turn-on/turn-off transient.
I have tried the Apex PA16 and found them not so special the sound was more laid back than GC but good in his own way.
Giorgio
tiroth said:
I use gainclones in my multiamped system even on horn tweeters without facing any problem. It is over 100dB efficient system and I dont have any turn-on/turn-off transient.
I have tried the Apex PA16 and found them not so special the sound was more laid back than GC but good in his own way.
Giorgio
Re: Re: Turn-on/turn-off DC transient
Yeah, it all depends on where things fall in each person's subjective spectrum. I found the hybrids more laid back compared to the monolithics but that was a plus for me because I felt the monolithics were too forward and etched for my taste.
I was a bit surprised when I read some of the reivews of the Gaincard about it having a warmth similar to tubes. Warmth isn't a term I'd use to describe my experience with the monolithics, even when I was using them with input transformers.
But then, that's just me.
se
giolight said:
Yeah, it all depends on where things fall in each person's subjective spectrum. I found the hybrids more laid back compared to the monolithics but that was a plus for me because I felt the monolithics were too forward and etched for my taste.
I was a bit surprised when I read some of the reivews of the Gaincard about it having a warmth similar to tubes. Warmth isn't a term I'd use to describe my experience with the monolithics, even when I was using them with input transformers.
But then, that's just me.
se
Question about samples
Hi!
Quite some time ago somebody here advised me to use National Sample program to get LM1875 and 3875 ...
Hmm - how does it look to order a sample - I'm currently surfing National web pages - there is a "24hr sample" button - I guess that's it - but what does that 24hr stands for??
Btw - are samples for us, who come from Europe for free (even without shipping costs) or how does that look like?!?
Thanks very very much for answers!
Hi!
Quite some time ago somebody here advised me to use National Sample program to get LM1875 and 3875 ...
Hmm - how does it look to order a sample - I'm currently surfing National web pages - there is a "24hr sample" button - I guess that's it - but what does that 24hr stands for??
Btw - are samples for us, who come from Europe for free (even without shipping costs) or how does that look like?!?
Thanks very very much for answers!
Re: What about more caps?
Yes. Though I can't vouch for the 3875 specifically. I found improvement in adding more capacitance until I got up to around 16,000uF after which it didn't seem to matter much. I started out with 1,000uF per rail and just kept paralleling 1,000uF caps.
However I've since ditched AC supplies completely and now run with 0uF.
se
Asen said:
Yes. Though I can't vouch for the 3875 specifically. I found improvement in adding more capacitance until I got up to around 16,000uF after which it didn't seem to matter much. I started out with 1,000uF per rail and just kept paralleling 1,000uF caps.
However I've since ditched AC supplies completely and now run with 0uF.
se
don't worry about the 'company name' thing. just put your own name.
they are pretty easy about hobbyists; they don't care much that you're using it for personal use. i wouldn't use a sample in something you're planning to sell for profit however.
to 'abbreviate' is to 'shorten', for example 'street' is abbreviated to 'st.'
oh, and the '24 hour sample' just means they have it in stock and can ship it out in 24 hours. they shipped mine pretty quickly. (i live in california though.)
don't know if shipping is free for europe or not. should be, i think.
they are pretty easy about hobbyists; they don't care much that you're using it for personal use. i wouldn't use a sample in something you're planning to sell for profit however.
to 'abbreviate' is to 'shorten', for example 'street' is abbreviated to 'st.'
oh, and the '24 hour sample' just means they have it in stock and can ship it out in 24 hours. they shipped mine pretty quickly. (i live in california though.)
don't know if shipping is free for europe or not. should be, i think.
Among the NatSemi monolithics, my favorite would likely be the metal-can LM12.
Nonetheless, like Steve, I also prefer hybrids to monolithics. It is too bad that the LH0101 and substitutes are no longer produced by any of the better-known companies who used to make them - National, Maxim, and Elantec (ELH0101). It does, however, seem like Film Microelectronics' FLH0101/FLH0101A may be a suitable sub - see:
http://www.satconelectronics.com/pages/32_linear_amplifiers.cfm?redirect=yes
However, I have never used any product by this company, so I have no idea how good it is or what it sounds like.
Otherwise, the closest sub available now appears to be Apex's PA02.
regards, jonathan carr
Nonetheless, like Steve, I also prefer hybrids to monolithics. It is too bad that the LH0101 and substitutes are no longer produced by any of the better-known companies who used to make them - National, Maxim, and Elantec (ELH0101). It does, however, seem like Film Microelectronics' FLH0101/FLH0101A may be a suitable sub - see:
http://www.satconelectronics.com/pages/32_linear_amplifiers.cfm?redirect=yes
However, I have never used any product by this company, so I have no idea how good it is or what it sounds like.
Otherwise, the closest sub available now appears to be Apex's PA02.
regards, jonathan carr
Re: What about more caps?
Strangely, it also worked best with the PSU caps skinned, and the chip caps left as normal...
I have tried lots of permutations, and the best sounding I have found so far is to use two 1000uf caps per rail, one next to the chip, as per normal, and another in the PSU.Asen said:
Strangely, it also worked best with the PSU caps skinned, and the chip caps left as normal...
sound testing
Alright guys.. Brian and I finally did some testing.. Specificially, we tested his leach amp against my gainclone. We were using brian's thors and a stock sony SACD player.
First we tried comparing some normal CD's, and at that point the gainclone and leach amp were pretty close in quality. The leach amp sounded kind of harsh in the highs, but that was about it. The gainclone was sounding good enough to make me happy, but it certainly wasn't living up to the hype.
Enter SACD.. Granted, this isn't Peter's cd player, but using SACD does give a significant boost in detail and imaging (compared to normal cd). "Paint it Black" by The 'Stones in SACD really opened our eyes to the Gainclone hype.. It was all there--dynamic, open, crisp and clear.. It made the leach amp sound muddy and harsh. It made me want to go out and get peter's cd player just so that I could see what this little amp could do. And ya know, I never had so much fun listening to the picking sounds on the guitar.. Also, I don't know who's been having problems getting bass out of their gainclone, but I thought it handled bass extremely well.
--shrug--
I was pleased.
Oh yeah, and then we compared my gainclone to his. Notice how he uses solens? Yup, they really don't sound all that good. Took the magic right out of the amplifier. So we bypassed them, and his gainclone sounded a lot more open, much more similar to mine. I also used Rikens instead of Allen-Bradley resistors, which I think gave my amp a slight edge..
fun stuff, this audio.
--Jordan
Alright guys.. Brian and I finally did some testing.. Specificially, we tested his leach amp against my gainclone. We were using brian's thors and a stock sony SACD player.
First we tried comparing some normal CD's, and at that point the gainclone and leach amp were pretty close in quality. The leach amp sounded kind of harsh in the highs, but that was about it. The gainclone was sounding good enough to make me happy, but it certainly wasn't living up to the hype.
Enter SACD.. Granted, this isn't Peter's cd player, but using SACD does give a significant boost in detail and imaging (compared to normal cd). "Paint it Black" by The 'Stones in SACD really opened our eyes to the Gainclone hype.. It was all there--dynamic, open, crisp and clear.. It made the leach amp sound muddy and harsh. It made me want to go out and get peter's cd player just so that I could see what this little amp could do. And ya know, I never had so much fun listening to the picking sounds on the guitar.. Also, I don't know who's been having problems getting bass out of their gainclone, but I thought it handled bass extremely well.
--shrug--
I was pleased.
Oh yeah, and then we compared my gainclone to his. Notice how he uses solens? Yup, they really don't sound all that good. Took the magic right out of the amplifier. So we bypassed them, and his gainclone sounded a lot more open, much more similar to mine. I also used Rikens instead of Allen-Bradley resistors, which I think gave my amp a slight edge..
fun stuff, this audio.
--Jordan
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