Using HT-processor with 2-channel setup...

[Jakob]

My question is regarding using my 2-channel setup in an HT setup.
I want to use my beloved ARC preamp in stereo mode and was thinking of connecting the processors front speaker pre-out to an input on the ARC. This will mean I need to have the ARC on when watching movies and have the gain-knob at a specific level. That I can live with.
Is there a risk that a strong signal from the pre-out on the processor can damage the input on the ARC pre-amp?

Any input appreciated,

Thanks, Jakob

[grumpy]

which ARC preamp? some have a processor pass-through capability...

(and no, a line-level out to your preamp in, e.g., AUX, should not hurt
the preamp).

[JBL 4645]

which ARC preamp? some have a processor pass-through capability...

(and no, a line-level out to your preamp in, e.g., AUX, should not hurt
the preamp).

Gumpy, I was wondering about the input voltage that it would allow before any possible clipping/distortion. Don’t most have voltage input of 3volts input??

[Jakob]

It's the ARC LS7, one of their most simple designs. No pass-through capability there.

The specs for the LS7 say: maximum input 20V. If the processor is capable of delivering 25V, what will happen then?

Thanks for your answers!

[JBL 4645]

It's the ARC LS7, one of their most simple designs. No pass-through capability there.

The specs for the LS7 say: maximum input 20V. If the processor is capable of delivering 25V, what will happen then?

Thanks for your answers!

I’d keep it down a few db, if I was you. What is the db to voltage value figure how many db makes up for 1volt? Something I haven't looked into myself, if I notice distortion I cut back on the db level on the main AVR.

I’ve just flipped though the user operating manual for the Yamaha DSR-70pro that acts as surround extra decoder for centre back and overheard matrix surround effects with the main AVR. Its input is rated at 2.0 volts rms and this was deigned for the signal output on say a Hi-Fi stereo vcr or laserdisc player, I’ve had no issues using it in any other way for the past 12 years.

I just had look on Google image at the preamp so it doesn’t have clipping LED warning indictor, I was thinking of those NAD preamps that often have clipping LED warning indictor to alert the user their overloading it.

[grumpy]

If the processor is capable of delivering 25V, what will happen then?

You would need to turn up the volume on the processor -way- too far to reach that level.
So don't do that. Most amplifiers will output their maximum levels with <2V input.

What you should be aiming for (IMO) is to get the same level out of the LS7 as what
you put in from the processor (volume setting that is "unity gain") ... or if the knob
were marked and calibrated, 13dB of attenuation using the volume control... since
the tube circuitry following adds 13dB to whatever comes out of the volume pot.

To answer your question more directly:
I don't see the LS7 schematic on arcdb, but I suppose you could exceed the volume control
(potentiometer) input spec (e.g. the ALPS 100Kohm "blue velvet" max operating AC
voltage is 30V), and damage it (maybe not totally smoke the unit, but cause it to
function noisily or erratically).

[Jakob]

Ok, that means that under normal circumstances I should be fine.


Thank you very much for this info.

Regards!

[brutal]

Ok, that means that under normal circumstances I should be fine.


Thank you very much for this info.

Regards!

FWIW, I ran my HT pre-amp mains output through a Yamaha C-70 pre-amp that I used to do bridging to a pair of M-80 amps. I just level matched the T-70 volume control with the volume output of the other HT channels using a combination of the HT built in room correction and a meter.

My setup was static, but if you knew the static position of the preamp volume control when you wanted to run HT, and reset it after running purely 2-channel, you'd have the best of both worlds. This is assuming you mean to run vinyl, high end CD, etc direct into the pre and limit TV, SAt, DVD, et.al. to the HT front end. Otherwise I see no improvement if you're simply inserting a pre betwixt the HT processor and external amps.

[JBL 4645]

FWIW, I ran my HT pre-amp mains output through a Yamaha C-70 pre-amp that I used to do bridging to a pair of M-80 amps. I just level matched the T-70 volume control with the volume output of the other HT channels using a combination of the HT built in room correction and a meter.

My setup was static, but if you knew the static position of the preamp volume control when you wanted to run HT, and reset it after running purely 2-channel, you'd have the best of both worlds. This is assuming you mean to run vinyl, high end CD, etc direct into the pre and limit TV, SAt, DVD, et.al. to the HT front end. Otherwise I see no improvement if you're simply inserting a pre betwixt the HT processor and external amps.

I thought that sound familiar the big fat large Yamaha with the large red LED barograph displays. I haven’t seen a picture of those in years, and had look on Google image, nice sweet.:) Mid 80's amp and there still going strongly.

[brutal]

I thought that sound familiar the big fat large Yamaha with the large red LED barograph displays. I haven’t seen a picture of those in years, and had look on Google image, nice sweet.:) Mid 80's amp and there still going strongly.

Many of them are expiring if they haven't been attended to. Yamaha, like many others of that era, are experiencing issues from the Sony Bond glue that was used all too generously to hold medium sized caps to the boards for assembly. Over time, the glue gets brittle and becomes corrosive and possibly a but conductive.

I've repaired about 20 Yamaha amps of this issue, only one truly stopped working properly before I attended to them, but real techs I know have many fixed dozens and the corrosive damage is quite evident.