Wow, never knew that was there!
I am going to pop the top off and see if I can re-wire the output so that it is in phase. For some silly reason it bothers me to have to hook up the red wire on the speaker leads to the negative terminal.
But I did just throw that switch. I built, some time ago a relay'd power strip so that the switched power plug on the back of the reciever controled a power strip to turn on and off my adcom amps. Now this will be set up the same way.
I am going to pop the top off and see if I can re-wire the output so that it is in phase. For some silly reason it bothers me to have to hook up the red wire on the speaker leads to the negative terminal.
But I did just throw that switch. I built, some time ago a relay'd power strip so that the switched power plug on the back of the reciever controled a power strip to turn on and off my adcom amps. Now this will be set up the same way.
Controlled Power Strip..
http://www.bitsltd.net/ConsumerProducts/index.htm
Also.
I have my auto power turned off. I learned from my Amp Three that it would power down in the middle of listening at low volumes.
I have had great luck with the sound of my AudioSource equipment. They just don't know how to get the little SnickSnacks correct..
Thanks,
Jeff P
http://www.bitsltd.net/ConsumerProducts/index.htm
Also.
I have my auto power turned off. I learned from my Amp Three that it would power down in the middle of listening at low volumes.
I have had great luck with the sound of my AudioSource equipment. They just don't know how to get the little SnickSnacks correct..
Thanks,
Jeff P
I've been reading this forum for quite a while and the ideas have been very helpful. Rather than making big mods, I decided to try to replace some of the components in the signal path with higher quality ones. Thanks to everyone for the valuable information posted on this board!
I began by bypassing the volume pots by switching the connectors as described in another post. I switched off the auto-on circuit. Then I replaced as much as I could in the signal path. I left the NE5532 opamp intact, but this is a personal preference.
The number in parentheses below indicate the number of each component needed. Total cost is about $45. Much of this cost is due to shipping ranging from $6-8 from each vendor, so it might be reasonable to buy a few spare components just for backup or in case one messes up the mod. Certainly one can use diffent brands of components, but I picked these to try to balance cost and quality.
INPUT CAPS
I began with the caps on the input board, replacing the Cerafines with Rubycons.
referenceaudiomods.com
(2) Rubycon ZA 47uf 35volts
RESISTORS
I replaced the stock resistors in the signal path. Since it was cheap and convenient to do so, I also replaced the resistors on the input board. They aren't necessarily in the signal path unless one uses the RCA outputs. When I was ordering, Mouser didn't sell the 12K ohm resistors except in bulk quantity, so I used 12.1K ohm instead.
mouser.com
(4) Vishay RN60D 2.2K ohm 71-RN60D2201F
(3) Vishay RN60D 12.1K ohm 71-RN60D-F-12.1K
(2) Vishay RN60D 22K ohm 71-RN60D-F-22K
(2) Vishay RN60D 100K ohm 71-RN60D-F-100K
This list shows the Resistor number as printed on the circuit boards, the value of the resistor, and the location.
Resistor K ohm Location
20 2.2 mainboard
31 100 mainboard
29 12 mainboard
30 22 mainboard
19 2.2 mainboard
25 100 mainboard
28 22 mainboard
41 12 mainboard
43 12 mainboard
63 2.2 input board
64 2.2 input board
COUPLING CAPS
I replaced the bipolar coupling caps on the mainboard with polypropylenes. Crimping the pins onto the bare wire and locking the pins in the plastic connector makes it much easier to install these large caps and provides a bit of strain relief vs. soldering bare wire onto the board.
e-speakers.com
(2) ClarityCap SA 4.7uf
mouser.com
(4) Crimp Snap-In Pins 571-1021073
(2) Connector 571-874995
OVERALL SOUND
The improvement in imaging was immediate. It was more focused. Tone sounded a bit dull and veiled at first, but this improved with a break in period of at least 50 hours, and clarity after break in is improved over original. Sound appears to be more transparent. I've done this mod on two amps now and the change is noticeable and reproducible.
Thanks for all of the informative posts! Good luck modding!
Best regards,
Tony
I began by bypassing the volume pots by switching the connectors as described in another post. I switched off the auto-on circuit. Then I replaced as much as I could in the signal path. I left the NE5532 opamp intact, but this is a personal preference.
The number in parentheses below indicate the number of each component needed. Total cost is about $45. Much of this cost is due to shipping ranging from $6-8 from each vendor, so it might be reasonable to buy a few spare components just for backup or in case one messes up the mod. Certainly one can use diffent brands of components, but I picked these to try to balance cost and quality.
INPUT CAPS
I began with the caps on the input board, replacing the Cerafines with Rubycons.
referenceaudiomods.com
(2) Rubycon ZA 47uf 35volts
RESISTORS
I replaced the stock resistors in the signal path. Since it was cheap and convenient to do so, I also replaced the resistors on the input board. They aren't necessarily in the signal path unless one uses the RCA outputs. When I was ordering, Mouser didn't sell the 12K ohm resistors except in bulk quantity, so I used 12.1K ohm instead.
mouser.com
(4) Vishay RN60D 2.2K ohm 71-RN60D2201F
(3) Vishay RN60D 12.1K ohm 71-RN60D-F-12.1K
(2) Vishay RN60D 22K ohm 71-RN60D-F-22K
(2) Vishay RN60D 100K ohm 71-RN60D-F-100K
This list shows the Resistor number as printed on the circuit boards, the value of the resistor, and the location.
Resistor K ohm Location
20 2.2 mainboard
31 100 mainboard
29 12 mainboard
30 22 mainboard
19 2.2 mainboard
25 100 mainboard
28 22 mainboard
41 12 mainboard
43 12 mainboard
63 2.2 input board
64 2.2 input board
COUPLING CAPS
I replaced the bipolar coupling caps on the mainboard with polypropylenes. Crimping the pins onto the bare wire and locking the pins in the plastic connector makes it much easier to install these large caps and provides a bit of strain relief vs. soldering bare wire onto the board.
e-speakers.com
(2) ClarityCap SA 4.7uf
mouser.com
(4) Crimp Snap-In Pins 571-1021073
(2) Connector 571-874995
OVERALL SOUND
The improvement in imaging was immediate. It was more focused. Tone sounded a bit dull and veiled at first, but this improved with a break in period of at least 50 hours, and clarity after break in is improved over original. Sound appears to be more transparent. I've done this mod on two amps now and the change is noticeable and reproducible.
Thanks for all of the informative posts! Good luck modding!
Best regards,
Tony
Well I can hear in the unit and on the speaker.. (Is that the torriod buzzin?) As soon as I turn on that amp the hum propegates into my speakers on the other amp too
I also noticed that the noisy amp faults (Green Power Light)
My other Amp 7 Never done this yet.. Just lit the internal green led...
RHC Trading is going to swap it out since only one of these amps has this problem.
I know some quiet amps were made..
Jeff
I also noticed that the noisy amp faults (Green Power Light)
My other Amp 7 Never done this yet.. Just lit the internal green led...
RHC Trading is going to swap it out since only one of these amps has this problem.
I know some quiet amps were made..
Jeff
Well, this thing must SUCK some major current on startup.
With the ol adcom 555mkII, I never had a problem.
Now, with this, I trip a 20 amp breaker about one in ten start ups.
I guess I really need to find a sequential startup strip.
The other amps on the same circuit are a marantz ma 500, the buttkicker, the sony receiver, and a smaller, 80 wpc amp for the couch shakers. Seems a little much when I list it out, eh?
Anyway, I really like the sound of this ebay amp! I am just surprised that it has a higher in-rush current than the old adcom.
With the ol adcom 555mkII, I never had a problem.
Now, with this, I trip a 20 amp breaker about one in ten start ups.
I guess I really need to find a sequential startup strip.
The other amps on the same circuit are a marantz ma 500, the buttkicker, the sony receiver, and a smaller, 80 wpc amp for the couch shakers. Seems a little much when I list it out, eh?
Anyway, I really like the sound of this ebay amp! I am just surprised that it has a higher in-rush current than the old adcom.
What do you think of the Seven T vs the Amp 300 vs a Carver zr1600?
I have Adcom 565 pre / 5500 power amp with Mirage M990 speakers and a Adire Audio Sub. I just got the 5500 to replace 2 NAD power envelope amplifiers used in a bi-amp setup, the 5500 works well but I wonder if I can do better with a digital amp?
I appreciate any and all opinions! Thanks!
I have Adcom 565 pre / 5500 power amp with Mirage M990 speakers and a Adire Audio Sub. I just got the 5500 to replace 2 NAD power envelope amplifiers used in a bi-amp setup, the 5500 works well but I wonder if I can do better with a digital amp?
I appreciate any and all opinions! Thanks!
I picked up one of these animals (needed a quick cheap party amp). I bypassed all the input crap ... took the signal directly from my tube DAC capacitor-coupled output ---> volume pots ---> Tripath input pins. Sound is considerably more immediate and highly resolved, though with evident HF edge (almost certainly the new coupling caps to the Tripath inputs). LF extension suits my purposes with the current coupling cap to Tripath pins = 0.23uF.
I am using the input board, though slightly modified by having removed the coupling caps, so:
DAC (cap coupled) ---> input board (no caps) ---> volume pots ---> coupling cap ---> input pins.
HFs are still a bit edgy, but improvements are, as expected, considerable by eliminating/improving all those caps/circuits.
DAC (cap coupled) ---> input board (no caps) ---> volume pots ---> coupling cap ---> input pins.
HFs are still a bit edgy, but improvements are, as expected, considerable by eliminating/improving all those caps/circuits.
Thanks to Tom I opened up my amp again and changed some things.
There is one strange thing I noticed; if you switch the connectors on the board to bypass the pots on the front, you no longer need the caps on the input board. If you bypass the caps with the pots still in place the amp won't come on.
I still have the signal running through the op-amp though. I did this because I would still like to be able to bridge the amp with the switch on the back. I did however upgrade the op-amp power supply components.
I think this is how I will leave them. They sound good.
I'm trying hard to keep myself from buying another one. I only have three, and four would be an even number. It's one heck of an amp for the money.
There is one strange thing I noticed; if you switch the connectors on the board to bypass the pots on the front, you no longer need the caps on the input board. If you bypass the caps with the pots still in place the amp won't come on.
I still have the signal running through the op-amp though. I did this because I would still like to be able to bridge the amp with the switch on the back. I did however upgrade the op-amp power supply components.
I think this is how I will leave them. They sound good.
I'm trying hard to keep myself from buying another one. I only have three, and four would be an even number
. It's one heck of an amp for the money.- Status
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