Rose CV23 Valve Pre

[tdiddey]

Hey:

I acquired one of these from a friend. Probably the only one that made
it to the states. Believe it's that last version with outboard power supply.
Great sound. Tried it with a number of amps Rega,Leben, Crimson, Prima Luna. The phono stage seesm good but I can't use it do to RFI..probably more of problem here in the states. Anybody know the history of this
preamp. I know Derek Gilligan of Kudos has one. I've been told the
builder has fallen off the map. Thanks.

Tdiddey

 

[Gerry]

Tdiddey

Is yours CV23 or RV23?
The off board PSU (only the transformer) were the later SE models.
Sean Edwards was the maker, I was in communication with him up to a few years ago. I think he move to NZ or South Africa.
If it is the RV23, great pre-amp. Ken Kessler loved it back in the day.

Regards
Gerard

 

[MattC]

Hi Tdiddey,

I believe Alex S of this parish had one - you could try PM-ing him?




cheers
Matt

 

[Patrick Dixon]

I suspect Derek Gilligan's may be Alex's old one.

 

[tdiddey]

Hey:

Thanks for the info Gerry. Let me look again I could have got the model# wrong.
I got it from a friend who used to be the US Neat dist. He bought it direct from
Edwards around 2002-03 as I recall. Thanks.

Tdiddey

 

[Gerry]

Tdiddy

It will be a RV23SE then at those dates. Very nice pre-amp indeed.
When the RV-23 came out KK compared it to a ARC SP8 if IRC. I have the article somewhere.
What RF noise are you getting?

 

[tdiddey]

Gerry:

Yeah the thing is amazingly good. The phono stage is set up for low
MC (The previous owner as do I use a Dynavector MC) and RFI
comes through. Same problem in another guys system where we tried it
w/ LO MC. I can tell it's a nice phonostage but the RFI 's too nasty.
Haven't tried ferrite clamps or any of that stuff..in my experience
they don't do jack. Luckily I have a Dynavector P75 and use the Rose as
a line stage and pulled the 2 phono 12au7's. Although I know the Rose phono
is supposed to be adjustable.

Tdiddey




QUOTE=Gerry;1149260]Tdiddy

It will be a RV23SE then at those dates. Very nice pre-amp indeed.
When the RV-23 came out KK compared it to a ARC SP8 if IRC. I have the article somewhere.
What RF noise are you getting?[/QUOTE]

 

[Gerry]

Tdiddy

The phono is adjustable here are Sean's instructions as he emailed them to me:

The pre-amp can now use moving coil or moving magnet cartridges by changing the position of the two pairs of mini switches on the right hand side of the circuit board (looking from the front). All switches in the off position = mm, all switches in the on position = mc. Please check that the pre-amp is set to the appropriate cartridge type. You should be able to see the switches through the cover.

The RFI could be the soldering going dry on the phono plugs. I did have an issue with this.

The other thing to be careful about, it was IMHO a design fault, is the possibility of a cracked PCB. There is a regulator in the PSU section of the PCB (on the left side, mid board) which has a cooling tower heatsink. The heatsink on mine was just too tall (1-2 mm) and when the top was screwed down on the amp it caused the PCB to crack at this point which caused intermittent problems, including noise.

This was when I discovered Sean had left the country!!!

Best

 

[tdiddey]

Hey Gerry:
It is a RV23 you were correct. Thanks for this info. I'll pop the top and
check for those things you mentioned.

Tdiddey

The phono is adjustable here are Sean's instructions as he emailed them to me:


The RFI could be the soldering going dry on the phono plugs. I did have an issue with this.

The other thing to be careful about, it was IMHO a design fault, is the possibility of a cracked PCB. There is a regulator in the PSU section of the PCB (on the left side, mid board) which has a cooling tower heatsink. The heatsink on mine was just too tall (1-2 mm) and when the top was screwed down on the amp it caused the PCB to crack at this point which caused intermittent problems, including noise.

This was when I discovered Sean had left the country!!!

Best[/QUOTE]

 

[ziggy72]

Hey:

I acquired one of these from a friend. Probably the only one that made
it to the states. Believe it's that last version with outboard power supply.
Great sound. Tried it with a number of amps Rega,Leben, Crimson, Prima Luna. The phono stage seesm good but I can't use it do to RFI..probably more of problem here in the states. Anybody know the history of this
preamp. I know Derek Gilligan of Kudos has one. I've been told the
builder has fallen off the map. Thanks.

Tdiddey

i have a copy of hifi choice from 1989 which the rose rv23 gets a glowing review. cost £395 at the time. the same issue has reviews of the concordant excelsior, audio innovations and audion cd1 amongst others. the audion came out on top for the line stages but wasn't recommended because it didn't have a phonostage which seemed strange as the other 2 mentioned were highly recommended.