No. The new version is not yet available.
You can't bypass the input ICs. They are part of the amplifier loop.
The JBL 2241h in that subwoofer would easily handle much more power than the LM 4780 can deliver. ...though, it is the first watts that count most, of course...
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Good afternoon, francolargo,
I need so little power from those D amps. They are absurdly high gain - I use them three or four notches from being off.
What is the gain of these? Not knowing my way around balanced circuits - I would assume a gain of 40 dB. Does the gain get halved by being balanced? If it is 40 that would still be less than the Crest but about double what my others have provide. I guess I will know for myself in a few days but it would be good to know what to expect. I have not seen this which doesn't preclude me missing it.
I have two of the Seismics which I have played around with. I have them facing forward and the back chamber more than halved. I think the first octave sounded very good in the stock configuration. The response got funny down there in my room. I am using the RYTHMIK subs for the first octave and they work extremely well with the Seismics. This is compared to nothing other than stock Seismics.
The two measure together very well - especially when both channels are measured together from the chair.
I think the Sympatico (sorry for the misspellings) will have plenty of power for them in a listening room.
What will matter is if they have better tonality than the Ds. I lived with them happily for a few years. The more I got the room right the more their sound started bothering me. An audio kook is always HOPING for an improvement.
After letting the one settle in for a week or so I will I have to put the other back in and hear.
I played with chip amps many years ago and enjoyed them. The Peter Daniel 3875 scheme. Never tried one of those on the Seismics since I figured they would have to work really hard. It was in my battery days and I doubt that combination would have been advantageous driving the JBL woofers.
I hope to be impressed and would gladly accept a long lasting placebo effect.
Then I will get another one.
With the JBLs I think it is the first five watts that matter ...
Take care,
I need so little power from those D amps. They are absurdly high gain - I use them three or four notches from being off.
What is the gain of these? Not knowing my way around balanced circuits - I would assume a gain of 40 dB. Does the gain get halved by being balanced? If it is 40 that would still be less than the Crest but about double what my others have provide. I guess I will know for myself in a few days but it would be good to know what to expect. I have not seen this which doesn't preclude me missing it.
I have two of the Seismics which I have played around with. I have them facing forward and the back chamber more than halved. I think the first octave sounded very good in the stock configuration. The response got funny down there in my room. I am using the RYTHMIK subs for the first octave and they work extremely well with the Seismics. This is compared to nothing other than stock Seismics.
The two measure together very well - especially when both channels are measured together from the chair.
I think the Sympatico (sorry for the misspellings) will have plenty of power for them in a listening room.
What will matter is if they have better tonality than the Ds. I lived with them happily for a few years. The more I got the room right the more their sound started bothering me. An audio kook is always HOPING for an improvement.
After letting the one settle in for a week or so I will I have to put the other back in and hear.
I played with chip amps many years ago and enjoyed them. The Peter Daniel 3875 scheme. Never tried one of those on the Seismics since I figured they would have to work really hard. It was in my battery days and I doubt that combination would have been advantageous driving the JBL woofers.
I hope to be impressed and would gladly accept a long lasting placebo effect.
Then I will get another one.
With the JBLs I think it is the first five watts that matter ...
Take care,
Greetings Rick,
If the first 5 watts are the ones you are most interested in, then you will enjoy the Sympatico.
The parts that come with the amp are very well chosen, IMO. There are comments back in this thread about cap substitutions. In a full-range setting, expect the sound to start out bright and take a good 3-4 weeks to stabilize. With 18" woofers, though, who knows? 🙂
Enjoy,
Frank
If the first 5 watts are the ones you are most interested in, then you will enjoy the Sympatico.
Working just from memory... I believe each side has a gain of 11X for a final amplification of 22X. But there is the option of tweaking the output gain and I raised each side to 14X to drive my (12" long-throw) woofers, to good effect. I used to run JBL 2235H drivers from a similar amp at 20X and and then at 28X. I liked the punch of slightly higher gain. But your drivers are crazy efficient... It's great to be able to tweak this amp to suit your space... [Sorry, I don't recall the formula for using the single gain-control thru-hole resistor. There is information over at the TPA support forum.]
The parts that come with the amp are very well chosen, IMO. There are comments back in this thread about cap substitutions. In a full-range setting, expect the sound to start out bright and take a good 3-4 weeks to stabilize. With 18" woofers, though, who knows? 🙂
Enjoy,
Frank
Thanks for your comments.
The SEISMIC is not a typical horn - being much too short - but it works. The compromise is that it does require some more power than one would expect. I do wonder if there is not a better driver to use than the JBL? I have a GREAT PLAINS 515ghp that I will eventually install and hear/measure. Of course, that driver will make the horn even "shorter".
The SEISMIC is quite unusual having a tiny throat and a gigantic front chamber with another smaller than expected throat from there. Worth a try with the 515s. Might have to return to 18s. Hoping i might find a better match with another driver for my room.
HEARING forward to using the SYMPATICO!
Take care,
The SEISMIC is not a typical horn - being much too short - but it works. The compromise is that it does require some more power than one would expect. I do wonder if there is not a better driver to use than the JBL? I have a GREAT PLAINS 515ghp that I will eventually install and hear/measure. Of course, that driver will make the horn even "shorter".
The SEISMIC is quite unusual having a tiny throat and a gigantic front chamber with another smaller than expected throat from there. Worth a try with the 515s. Might have to return to 18s. Hoping i might find a better match with another driver for my room.
HEARING forward to using the SYMPATICO!
Take care,
Nine months late in providing feedback 😀, but it would be cool if the Sympatico board supported dual bridge rectification and also support for 4-pole power caps
External access to control the chip's Mute Select would also be useful.
I find dual bridge rectification gives a noticeable improvement (as does using Mundorf or Jensen 4-pole power caps).
I've built a few Sympaticos. They have a pleasingly warm MOSFET amp sound to them and their small size makes them ideal for use in my active digital xover builds requiring multiple amps - altho I only use them to drive the tweeter and mid driver (I use D-Class amps for the lows)