- Joined
- Oct 14, 2013
- Messages
- 31
I'm a man. And I can admit when I need help..
Help!!
I am retiring my vintage receivers (They are working perfectly, but are now worth so much I hate to lose them to daily usage)
I typically rotate a Harman Kardon 800+ and a Sansui QRX-7001.
My signal path with both the SM V1 and the SM V3 are as follows:
My external sources are connected to a 5 position 2 channel RCA switch box
1: CD
2: Phono Preamp
3: Linux Micro PC
3: FIIO Flac Player
4: BluRay
The output of the RCA Switcher connect to the input of the SM. Input level on the V3 is set just below clipping. As it was connected directly to the inputs, once set I did not have to vary the input gain\cut.
SM output is sent to the "AUX" 4 channel input of the 800+ or 7001
Each channel has discrete tone and a 4 gang volume control.
Life was good. Birds sung, brandy flowed freely. My motor was shiny clean .. Elvi was happy man!
New Stack of Kit
I retired the 5 way switcher; the new preamp has 6 dual channels of discrete relay switching
Preamp = Vincent SA-32 (A two channel hybrid\tube pre. Possibly someone knows what this is a copy\clone of)
Preamp has defetable tone, no low or high filter but has motorized volume
Tone\Volume processed audio from preamp out to stereo input of SM
SM3, input level must be constantly adjusted, due to variable level post Preamp
Quad output from SM to two matched Aiyama A07 stereo amp modules. The integrated volume control is set to maximum.
Result?
Very high noise floor\hiss. This is the background procession\amplification stage from the SM.
Brandy glasses broke, birds fouled my motor .. Elvi was troubled..
OK; time to experiment.
Power off the SM effectively placing it in passthrough mode. No hiss
Remove the SM fully from the equation, with no input and both the preamp and amp module volume in minimum cut (Max volume) No hiss
Short the inputs of the SM, Power the SM on, set the volume control on the amp module to min cut (Max volume). Hiss
So; what I have learned.
Even with no input; and the input level on the SM set to maximum cut (Min volume) the processor\preamplification gain hiss from the SM is present. This is not unexpected, stuff has to happen; and that takes energy..
So; the following begs to be answered?
Why was this not detectable with the 800+ and the 7001?
Here is the Scat of the 7001
Input is through "AUX"
Switches on F-2423 are 4 channel enable and tape monitor; tone tweaking and then volume.
OK. now we have our answer. The 800+ \ 7001 amplify the sum of the selected inputs AND the processing background. I cant hear it, as its buried deep in the media.
With the new kit; with no signal into the SM, we are still amplifying any signal from the SM, at 100 %
The SM is the "Last" In the audio chain, and amplified at whatever the Amp modules can muster. at an advertised 300WPer and a GAIN:21.5db I can see why.
Here is what "We" want. (Yes. you want one too.. )
A preamp that will take many inputs, has a "Quad" input before the tone\amp circuits and Quad out to the amps.
So, Is there a modern multichannel Pre that will work?
Love to have relay switched inputs, motorized 4 channel volume and full tonal control.
Comments welcome!!
Help!!
I am retiring my vintage receivers (They are working perfectly, but are now worth so much I hate to lose them to daily usage)
I typically rotate a Harman Kardon 800+ and a Sansui QRX-7001.
My signal path with both the SM V1 and the SM V3 are as follows:
My external sources are connected to a 5 position 2 channel RCA switch box
1: CD
2: Phono Preamp
3: Linux Micro PC
3: FIIO Flac Player
4: BluRay
The output of the RCA Switcher connect to the input of the SM. Input level on the V3 is set just below clipping. As it was connected directly to the inputs, once set I did not have to vary the input gain\cut.
SM output is sent to the "AUX" 4 channel input of the 800+ or 7001
Each channel has discrete tone and a 4 gang volume control.
Life was good. Birds sung, brandy flowed freely. My motor was shiny clean .. Elvi was happy man!
New Stack of Kit
I retired the 5 way switcher; the new preamp has 6 dual channels of discrete relay switching
Preamp = Vincent SA-32 (A two channel hybrid\tube pre. Possibly someone knows what this is a copy\clone of)
Preamp has defetable tone, no low or high filter but has motorized volume
Tone\Volume processed audio from preamp out to stereo input of SM
SM3, input level must be constantly adjusted, due to variable level post Preamp
Quad output from SM to two matched Aiyama A07 stereo amp modules. The integrated volume control is set to maximum.
Result?
Very high noise floor\hiss. This is the background procession\amplification stage from the SM.
Brandy glasses broke, birds fouled my motor .. Elvi was troubled..
OK; time to experiment.
Power off the SM effectively placing it in passthrough mode. No hiss
Remove the SM fully from the equation, with no input and both the preamp and amp module volume in minimum cut (Max volume) No hiss
Short the inputs of the SM, Power the SM on, set the volume control on the amp module to min cut (Max volume). Hiss
So; what I have learned.
Even with no input; and the input level on the SM set to maximum cut (Min volume) the processor\preamplification gain hiss from the SM is present. This is not unexpected, stuff has to happen; and that takes energy..
So; the following begs to be answered?
Why was this not detectable with the 800+ and the 7001?
Here is the Scat of the 7001
Input is through "AUX"
Switches on F-2423 are 4 channel enable and tape monitor; tone tweaking and then volume.
OK. now we have our answer. The 800+ \ 7001 amplify the sum of the selected inputs AND the processing background. I cant hear it, as its buried deep in the media.
With the new kit; with no signal into the SM, we are still amplifying any signal from the SM, at 100 %
The SM is the "Last" In the audio chain, and amplified at whatever the Amp modules can muster. at an advertised 300WPer and a GAIN:21.5db I can see why.
Here is what "We" want. (Yes. you want one too.. )
A preamp that will take many inputs, has a "Quad" input before the tone\amp circuits and Quad out to the amps.
So, Is there a modern multichannel Pre that will work?
Love to have relay switched inputs, motorized 4 channel volume and full tonal control.
Comments welcome!!