safetyman said:
Thanks Leo, but I am sure you will want to receive them soonest. Anyways, they will be out tomorrow.
Just as long as you are fit🙂
Thanks again
t., I should be able to move around tomorrow. It's 3.15am here right now and I am trying to figure out the LM4780 GC that I completed a few hours ago. It's louder on one side initially and after a few minutes, the right channel which is the louder channel, now has no sound whatsoever. 🙁 *Sigh* Think I am going to call it a night. Getting some sleep to heal the broken spirit and try to troubleshoot tomorrow.
Any suggestions?
Any suggestions?
safetyman said:
3:15am😱 I thought I had problems sleeping
You can mail me or start a new thread regarding your LM4780 problem, I've not used that chip but I'm sure we can hopefully get it sorted
Weird i got some 4780 recently and was going to try them in some form soon.
Well said t.
Rudi has done us a great service with his board design and thanks must also be given to Carlos for his initial design.
And you are right it is clearly a fantastic sounding preamp in its initial form, my god its quite stunning with 'Live' recorded music. Quite spooky.
I have been running mine with a Nuuk SMPS powered AMP3, all i can say is i have never heard anything like it before. Quite a wonderful sounding setup, I am sure i could never afford a commercial system that gave anywhere near this sound.
P.S. how are you going to use the SMPS to power this setup? USe the +/- 12v rails, wont that be a little low even if you dial it up a bit?
phil
Well said t.
Rudi has done us a great service with his board design and thanks must also be given to Carlos for his initial design.
And you are right it is clearly a fantastic sounding preamp in its initial form, my god its quite stunning with 'Live' recorded music. Quite spooky.
I have been running mine with a Nuuk SMPS powered AMP3, all i can say is i have never heard anything like it before. Quite a wonderful sounding setup, I am sure i could never afford a commercial system that gave anywhere near this sound.
P.S. how are you going to use the SMPS to power this setup? USe the +/- 12v rails, wont that be a little low even if you dial it up a bit?
phil
filholder said:
Well I tried a pair of 12v 7Ah batteries and they powered it fine🙂
Infact the sound was nice
guys why don't you try something more serious regarding amps. why not build the Amp2 that 41hz offers. that coupled to a 700va transformer and 30 000va per rail with ad815 to do the front end is just sweeeeeeet. i have build several tripath amps and the TA2350 is by far the best. i build mine form the original tripath board but the 41hz is a much cheaper option.
Some considerations for the R&D team
Introduction:
I am a fan of tight bass, I really am. Everything gets better.
Here's a test: buy (if you don't have it) Rebecca Pidgeon's "The Raven" hybrid CD/SACD.
Listen to track 12: "Spanish Harlem".
It has seizmic bass. You must hear it going very low BUT tight. Does anything vibrate? If you go to another room and leave the volume LOUD do you still hear the tight bass?
It is very rewarding when you do. If you don't, there still work to do.
Source component(s), preamp, power amp, speakers... everything counts.
Now to what matters, the pre.
I also think that Jung super-regs are a natural improvement. Constant current, low impedance.
I have a dual board I may try (gently sent by forum member Coffin).
BUT I must make a remark, regarding the LM317/337 regs.
On my pre I use them on-board, very near to the AD815 chip (a couple of cm). I think this is important.
The AD815 asks for more current than a normal op-amp. Otherwise you must have bigger caps on the AD815's PSU pins. But this is a very fast chip and then other lings may be lost, snubberizing to the rescue.
I have calculated (for another project) snubber values to use after the LM317/337 regs.
These are 0.47R + 22uF.
I didn't try it here, but for the most adventurous (!) that are using LM317/337 regs on this pre, try it.
I also recommend an RCRC (or RCLC) unregulated PSU before the regs, but this I have already said.
At last, a challenge to Charles (analog_sa): try this pre, man. 😎
Introduction:
I am a fan of tight bass, I really am. Everything gets better.
Here's a test: buy (if you don't have it) Rebecca Pidgeon's "The Raven" hybrid CD/SACD.
Listen to track 12: "Spanish Harlem".
It has seizmic bass. You must hear it going very low BUT tight. Does anything vibrate? If you go to another room and leave the volume LOUD do you still hear the tight bass?
It is very rewarding when you do. If you don't, there still work to do.
Source component(s), preamp, power amp, speakers... everything counts.
Now to what matters, the pre.
I also think that Jung super-regs are a natural improvement. Constant current, low impedance.
I have a dual board I may try (gently sent by forum member Coffin).
BUT I must make a remark, regarding the LM317/337 regs.
On my pre I use them on-board, very near to the AD815 chip (a couple of cm). I think this is important.
The AD815 asks for more current than a normal op-amp. Otherwise you must have bigger caps on the AD815's PSU pins. But this is a very fast chip and then other lings may be lost, snubberizing to the rescue.
I have calculated (for another project) snubber values to use after the LM317/337 regs.
These are 0.47R + 22uF.
I didn't try it here, but for the most adventurous (!) that are using LM317/337 regs on this pre, try it.
I also recommend an RCRC (or RCLC) unregulated PSU before the regs, but this I have already said.
At last, a challenge to Charles (analog_sa): try this pre, man. 😎
Hi Carlos
thanks for the suggestion.
Ok these snubbers. if i use dual regs do i use it after each one or after the last one
analog-sa. i will have a test box for the pre soon. if you are in the jhb region you are welcome to try it.
thanks for the suggestion.
Ok these snubbers. if i use dual regs do i use it after each one or after the last one
analog-sa. i will have a test box for the pre soon. if you are in the jhb region you are welcome to try it.
Rebecca Pidgeon's "The Raven" , Spanish Harlem, yes thats an excellent track played through the right system, can you hear what sounds like a book being dropped in the backgound at the right hand side near the start of that track🙂 also those twanging strings
I know what you mean regarding the bass on this one Carlos😉
This track is also one where the Schottky diodes in my amps gave far superior bass than any other type diode I tried
Anyway, excellent advice as always Carlos😎
I know what you mean regarding the bass on this one Carlos😉This track is also one where the Schottky diodes in my amps gave far superior bass than any other type diode I tried
Anyway, excellent advice as always Carlos😎
rudi said:
This is Carlos AD815 pre thread, so I won't adulterate the track. Last thing, Rudi, the X-Caliber and this pre is the next in line. 😀
SORRY CARLOS....🙄
safetyman said:
We all have made projects that have not worked first time so don't worry about it🙂
NOW GET SOME SLEEP😀
Amen to bass!
Carlos,
I too am a fan of the tight deep stuff! There is nothing like the growl of a well played electric or acoustic bass.
My favourite bassist is Brian Bromberg. I especially recommend Wood, Wood II, Choices, The Acoustic Project. Brian differs from most bassist in that he is not afraid to play really low notes, and yet manages to avoid making the bass sound fat and thick.
Ask Rudi!
Onto something else. Has anyone seen this:
http://home.comcast.net/~walt-jung/wsb/PDFs/Composite_Line_Driver_with_Low_Distortion.pdf
This is a "composite line stage" by WALT JUNG. He uses a AD825 followed by the AD815, all direct coupled.
Seems easy enough to build. Perhaps we should try and compare with the AD815?
Ciao
Ryan
Carlos,
I too am a fan of the tight deep stuff! There is nothing like the growl of a well played electric or acoustic bass.
My favourite bassist is Brian Bromberg. I especially recommend Wood, Wood II, Choices, The Acoustic Project. Brian differs from most bassist in that he is not afraid to play really low notes, and yet manages to avoid making the bass sound fat and thick.
Ask Rudi!
Onto something else. Has anyone seen this:
http://home.comcast.net/~walt-jung/wsb/PDFs/Composite_Line_Driver_with_Low_Distortion.pdf
This is a "composite line stage" by WALT JUNG. He uses a AD825 followed by the AD815, all direct coupled.
Seems easy enough to build. Perhaps we should try and compare with the AD815?
Ciao
Ryan
When i get time i might try a version of Rudis board but running of one of Nuuks SMPS.
Any idea what level of capaticance i should use for this setup, i was thinking of keeping all the exhisting local capacitance the same ie the capacitance near the legs of both the ad815 and the 2134. However what shoud be used before this, if any?
This si just and idea and i ma going to trying it purely by chopping up Rudis board design. It just i have enough of everthing to try this and it seem like an interesting setup to try, i might dial up the SMPS to as high a output as i can since i gess the AD815 will work better closer to 15v
Phil
Any idea what level of capaticance i should use for this setup, i was thinking of keeping all the exhisting local capacitance the same ie the capacitance near the legs of both the ad815 and the 2134. However what shoud be used before this, if any?
This si just and idea and i ma going to trying it purely by chopping up Rudis board design. It just i have enough of everthing to try this and it seem like an interesting setup to try, i might dial up the SMPS to as high a output as i can since i gess the AD815 will work better closer to 15v
Phil
Fill, you are in luck because t has gone ahead of you! 😉
He's at work at present so I hope he won't mind me giving you some advice.
He used 10K (caps on the output of the SMPS and also found it sounded better with the wires (from SMPS to pre) twisted.
He did say caps (plural) so I am guessing that he used two SMPS.
And from what he said, it would be a good idea to up the voltage as far as you can!
I'll wait for him to post his impressions as it may influence you if you are going to try this for yourself today! 😉
He's at work at present so I hope he won't mind me giving you some advice.
He used 10K (caps on the output of the SMPS and also found it sounded better with the wires (from SMPS to pre) twisted.
He did say caps (plural) so I am guessing that he used two SMPS.
And from what he said, it would be a good idea to up the voltage as far as you can!
I'll wait for him to post his impressions as it may influence you if you are going to try this for yourself today! 😉
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