[stereocilia]

I have a Jeff Rowland Consonance preamp (which I love), and a local dealer has a used single-owner Model 1 amplifier which matches it perfectly.  It was reportedly checked and measured and works within spec.  It's never been repaired but he's not exactly sure how old it is.  So, how worried should I be about buying an amp of this age?  It's built like an heirloom, by the way.

[sts9fan]

Worst case in a few years (as if you could keep an amp that long) we can change out the caps.

[stereocilia]

Good points.   I'll take a peek inside.  It does need a new lamp in the switch but that's trivial.  Yes, I do have a history of not keeping gear, but I've had the preamp for years.  I just wish I could afford the matching amp and run them bridged as the previous owner did. 

[stereocilia]

So, the heat sinks on the right side are warm, just like I imagine they should be, while the left channel heat sinks are barely above room temperature.  The difference is marked.     McDLT anybody? 

[sts9fan]

That does not sound good.   

[stereocilia]

Maybe it just needs to be rebiased.  But, why would a solid-state amp ever need to be re-biased?  Is it because it lived its whole life as a mono amp?  The dealer says he will contact their tech who is very familiar the design and get back to me.  Fortunately, I'm not committed to the purchase.

[JakeJ]

Even SS gear can suffer drift of operating parameters over time.  The A'gon bluebook says it was released in 1989 so it has been in service for sometime.

I recently sent my JRDG Coherence One Series II preamp in to JRDG in Colorado and they really bent over backwards to take care of me.  It had a bad connector on the outputs of the power transformer (molex style connector to a pin header on the PS motherboard) They repaired it and replaced all the modules in the linestage with newer quieter ones and the difference was amazing.  Lower distortion, noise floor, better dynamics, better resolution, and a higher level of transparency.  I have it paired to a Model 5 stereo amp and the combo is without a doubt the finest SS equipment to grace my home, although that doesn't hold much weight as I haven't had much exposure to other highly regarded SS gear.

About the best I have experienced before the JRDG kit is a McCormack ALD-1 preamp that had SMc Audio's Rev A+ Gold upgrade.  While good it wasn't as good as the JRDG.

If it's an option then you'd get back a amp you'll be happy with for the long haul, even if that's only a couple of years. 

Hope that helps,Jake

[stereocilia]

That really does help, Thank you.  The amp comes in a wooden crate which will have an impact on the shipping cost if it does need to go back JRDG.  No doubt about it, the amp is gloriously musical.  But, I am disinclined to commit to buying it if it needs major service.

[stereocilia]

I decided not to purchase the amp, after all.  I think it would be wiser to save my money and open more options.   Thanks to all who responded.

[Noseyears]

I decided not to purchase the amp, after all.  I think it would be wiser to save my money and open more options.   Thanks to all who responded.

Let us know what you get..or if you need more recommendations on Amps.

Cheers

[stereocilia]

Thanks.  I was thinking about an NAD C275bee.  I have an NAD C 320bee in a second system which sounds terrific.  The C275 is in my price range but I would probably wish I had saved my money for a modwright KWA 100 (or something).

[MLAS]

[quote author=JakeJ
I recently sent my JRDG Coherence One Series II preamp in to JRDG in Colorado and they really bent over backwards to take care of me.  It had a bad connector on the outputs of the power transformer (molex style connector to a pin header on the PS motherboard) They repaired it and replaced all the modules in the linestage with newer quieter ones and the difference was amazing.  Lower distortion, noise floor, better dynamics, better resolution, and a higher level of transparency.  I have it paired to a Model 5 stereo amp and the combo is without a doubt the finest SS equipment to grace my home, although that doesn't hold much weight as I haven't had much exposure to other highly regarded SS gear.
[/quote]
Hi Jake,

Just received my JRDG Coherence One Series II from California.
My molex style connector fro the secondary side of the transformer is also broken. It's probably due the heat generated from the two varistors in front of them or the three bridge rectifiers.
I saw you send yours to Jeff Rowland for repair and upgrading the 4 line modules.
Can you tell me what Jeff charged you for this upgrade and repair because at this time he does not respond to my inquiry.

I have DC on the outputs also after approx. half an hour warming up.
Then the outputs mute and my ML-2's trip there circuitbreakers...

Main unit smelled like electrolytic fluid from the condensators so I'm gonna replace all the lytics in the powersupply and mainunit and hope the malfunctioning is over.
Worst case scenario it's not and the I have to replace the modules.

Hope to hear from you.

Thanks in advance.