I have read so many threads, reviews, etc....my head is spinning. I have also tried to get the schematics to the circuit to no avail and tried to draw it out but get a headache doing so.
I believe only need to upgrade the high pass, set at 80Hz, as the low pass will be fine enough with the stock JRC4580D opamps. The plan is to upgrade the caps for the high pass and power supply as needed. DIP soldered in opamps, I could solder in sockets if need to test more than one opamp model for the upgrade.
Some state the 4580 is fine for this application but I find that hard to accept even though feeding to a tube amp(this amp has a very high bandwidth and a bit less of that smooth tube sound, more like a hybrid tube/transistor sound)
I prefer the smoother sounding opamps though I love the sound of the amp and speakers I could live with toning it down a bit more but not too much.
I was recommended to try the OPA2209 as an easy option but that it might not make enough difference to bother. I have read about most all the higher end opamps and many seem just to difficult to use not knowing the circuit design.
I just want to do something worthwhile, cost effective(if only two opamps and some caps cost is not an issue of course) and I just like to change at least something like I did on the speaker upgrades and now have to build new bass horns to fit, building the subs into the back wall of the RV, tube amp upgrades, DIY cables, etc....
PS is +/-15vdc as measured.
4580 on far right is part of the highpass, believe the one to its left is as well but kept getting stuck trying to nail it down.
Far left and the one to its right seem to only be tied to the low pass section.
Switch by the RCA connectors is the subsonic filter, middle is the bass boost, far left is the 12 volt trigger selector, on/off/auto
There is a much larger board in the front of the unit with many 4580s on it and controls for the EQ, etc...
Pretty sure just the two right 4580s have anything to do with the high pass filter.
System, rather low end compared to some but more than enough for our enjoyment. in our full time RV.
Mostly stream through a PC, Laptop, TV, QoBuz, no MQA and a modest CD, DVD and BD library through a good Panasonic BD player.
I am going to investigate steamers to see if really that important or not.
For now, Topping e30 DAC using Li battery, tested various power adapters, USB, like the battery the best. I am researching a bit higher end DACs, like AKG chips.
Baby Sophia tube amp with all pertinent upgrades and best tubes I could find, cheap so bought several spare sets.
SA1000 sub amp, 1kw rated AB, been using it a long time, it works great and has a single band variable EQ, Q and phase as well as variable low pass xover, fixed high pass at 80hz which might be just fine since the main speakers only go to 70hz and drop off from there.
Edgarhorn Slimline speakers(Dr Bruce was a great guy, glad I got to know him) huge oil filled caps, foil inductors, better resistors, Fostex super tweeter.
Dual Image Dynamics ID15 subs, sealed enclosures(another great guy I got to know, Eric Stevens)
I can take measurements though no longer have test gear other than a decent DMM and a good solder station as well as a higher end solder vacuum tool.
Any help will be greatly appreciated🙂
Thanks,
Rick
I believe only need to upgrade the high pass, set at 80Hz, as the low pass will be fine enough with the stock JRC4580D opamps. The plan is to upgrade the caps for the high pass and power supply as needed. DIP soldered in opamps, I could solder in sockets if need to test more than one opamp model for the upgrade.
Some state the 4580 is fine for this application but I find that hard to accept even though feeding to a tube amp(this amp has a very high bandwidth and a bit less of that smooth tube sound, more like a hybrid tube/transistor sound)
I prefer the smoother sounding opamps though I love the sound of the amp and speakers I could live with toning it down a bit more but not too much.
I was recommended to try the OPA2209 as an easy option but that it might not make enough difference to bother. I have read about most all the higher end opamps and many seem just to difficult to use not knowing the circuit design.
I just want to do something worthwhile, cost effective(if only two opamps and some caps cost is not an issue of course) and I just like to change at least something like I did on the speaker upgrades and now have to build new bass horns to fit, building the subs into the back wall of the RV, tube amp upgrades, DIY cables, etc....
PS is +/-15vdc as measured.
4580 on far right is part of the highpass, believe the one to its left is as well but kept getting stuck trying to nail it down.
Far left and the one to its right seem to only be tied to the low pass section.
Switch by the RCA connectors is the subsonic filter, middle is the bass boost, far left is the 12 volt trigger selector, on/off/auto
There is a much larger board in the front of the unit with many 4580s on it and controls for the EQ, etc...
Pretty sure just the two right 4580s have anything to do with the high pass filter.
System, rather low end compared to some but more than enough for our enjoyment. in our full time RV.
Mostly stream through a PC, Laptop, TV, QoBuz, no MQA and a modest CD, DVD and BD library through a good Panasonic BD player.
I am going to investigate steamers to see if really that important or not.
For now, Topping e30 DAC using Li battery, tested various power adapters, USB, like the battery the best. I am researching a bit higher end DACs, like AKG chips.
Baby Sophia tube amp with all pertinent upgrades and best tubes I could find, cheap so bought several spare sets.
SA1000 sub amp, 1kw rated AB, been using it a long time, it works great and has a single band variable EQ, Q and phase as well as variable low pass xover, fixed high pass at 80hz which might be just fine since the main speakers only go to 70hz and drop off from there.
Edgarhorn Slimline speakers(Dr Bruce was a great guy, glad I got to know him) huge oil filled caps, foil inductors, better resistors, Fostex super tweeter.
Dual Image Dynamics ID15 subs, sealed enclosures(another great guy I got to know, Eric Stevens)
I can take measurements though no longer have test gear other than a decent DMM and a good solder station as well as a higher end solder vacuum tool.
Any help will be greatly appreciated🙂
Thanks,
Rick
Opamps (that are good enough for audio) don't have a sound, they are flat/neutral by definition(*). Randomly swapping opamps without understanding things like decoupling requirements, input bias currents, maximum loading is perhaps asking for trouble.
(*) Perhaps the only exception to this is noise-floor, and that's only likely to be audible in a mic or phono preamp. But for line-level signals from DC to 20kHz you aren't going to be able to hear the difference as decent audio opamps are usually 0.001% THD or less, orders of magnitude below the ability of human ears to detect.
(*) Perhaps the only exception to this is noise-floor, and that's only likely to be audible in a mic or phono preamp. But for line-level signals from DC to 20kHz you aren't going to be able to hear the difference as decent audio opamps are usually 0.001% THD or less, orders of magnitude below the ability of human ears to detect.
What a timely thread. My Dayton Audio SA 1000 amp is not putting hardly any thing out.
I can turn the volume up all the way and I can just feel a little vibration if I put my hand on the woofer suround.
I took the lid off and I can see little bits of splatter on a connector by D11. I`ll try and post pictures.
The device at D11 looks shot. One of the larger caps is kind of loose and there looks to be some debris down in there.
If someone can tell me what that is at D11 I`ll order one and change out the two larger caps too.
Any help would be great.
Steve
I can turn the volume up all the way and I can just feel a little vibration if I put my hand on the woofer suround.
I took the lid off and I can see little bits of splatter on a connector by D11. I`ll try and post pictures.
The device at D11 looks shot. One of the larger caps is kind of loose and there looks to be some debris down in there.
If someone can tell me what that is at D11 I`ll order one and change out the two larger caps too.
Any help would be great.
Steve
Length & diameter determine if it is half watt like a 1n4004 or bigger like a diodes.inc A6. A6 also has fatter leads.
Whether it has .7 v drop like 1n4004 or 0.3 like MBR1100 schottky is up to you. Use diode scale of DVM and measure it or similar ones forwards.
On second thought in 1st picture appears to be no bigger than 1n4148 D14. Zeners are usually grey or brown, so could be schottky. If those are switcher nfets below & to left, most surely schottky. If mains voltage gets in there, make PIV 400 v. No lower PIV than the two big caps voltage rating below.
Whether it has .7 v drop like 1n4004 or 0.3 like MBR1100 schottky is up to you. Use diode scale of DVM and measure it or similar ones forwards.
On second thought in 1st picture appears to be no bigger than 1n4148 D14. Zeners are usually grey or brown, so could be schottky. If those are switcher nfets below & to left, most surely schottky. If mains voltage gets in there, make PIV 400 v. No lower PIV than the two big caps voltage rating below.
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You have to measure the voltage drop with diode scale of DVM. Then measure body size and diameter. Choices are in post 6.
Ok...I don`t have the tools nor know how to do that.
Probably easier to send the board off somewhere , it`s only the size of an index card and would easily fit in a small padded envelope.
Thanks
Steve
Probably easier to send the board off somewhere , it`s only the size of an index card and would easily fit in a small padded envelope.
Thanks
Steve
