London Decca Super Gold cartridge

TroutMask · 13-03-2013 2:23pm #1

what phono preamp is recommended for a London Decca Super Gold cartridge?

Slaphead07 · 13-03-2013 7:13pm

TroutMask wrote: »

what phono preamp is recommended for a London Decca Super Gold cartridge?

Find out if it's Moving Magnet (MM) or moving coil (MC) as not all phono stages will suit one or the other. Assuming that cart is in good nick you'll need a serious phono stage to pair with it and a good arm and deck.

Although opinion is divided they're generally considered a very good cart but they do require absolutely perfect setup in a quality system.

TroutMask · 13-03-2013 10:55pm

Got arm, deck, nice stages, step-up traffos etc. Decca is neither MC or MM - it's like its own design. It is in good nick, retipped and I checked it under a microscope and it's fine. I'm wondering if there are any Decca cartridge users that can recommend a preamp. I have a Conrad Johnson PV4 preamp and step-up traffos for same BTW.

Slaphead07 · 14-03-2013 4:27pm

TroutMask wrote: »

Got arm, deck, nice stages, step-up traffos etc. Decca is neither MC or MM - it's like its own design. It is in good nick, retipped and I checked it under a microscope and it's fine. I'm wondering if there are any Decca cartridge users that can recommend a preamp. I have a Conrad Johnson PV4 preamp and step-up traffos for same BTW.

Ask over on www.tirnahifi.org where the guys use higher end stuff than here.

I've only ever heard of those carts but know very little about them .

Fuzzy Clam · 14-03-2013 11:36pm

It's probably moving iron and load impedance 47K so a MM preamp will do I suppose. No need for the transformers.

TroutMask · 14-03-2013 11:40pm

Yeh, I was gonna try it with the C J - I have a PrismSound as well, i'm sure one of them will work

Slaphead07 · 15-03-2013 2:30am

Fuzzy Clam wrote: »

load impedance 47K

this much I do know!:D

TroutMask · 15-03-2013 12:44pm

Slaphead07 wrote: »

this much I do know!:D

Hmm, and my car has medium-sized wheels :pac:

Don't worry, I'll find a good pre - I was just being lazy and posting here first. The London Decca i s a very interesting design - I was surprised to learn that it is supposed to be really good for rock! I had it pegged as a polite 'classical only' cart. Looking forward to playing my Motorhead records with such a classy cartridge

Slaphead07 · 15-03-2013 3:59pm

TroutMask wrote: »

Hmm, and my car has medium-sized wheels :pac:

Don't worry, I'll find a good pre - I was just being lazy and posting here first. The London Decca i s a very interesting design - I was surprised to learn that it is supposed to be really good for rock! I had it pegged as a polite 'classical only' cart. Looking forward to playing my Motorhead records with such a classy cartridge

The guys on the UK sites, hifiwigwam or pinkfishmedia.net would be more familiar with Decca products. Probably worth a visit before spending money. Good luck with it, it sounds, at the very least, interesting!

TroutMask · 15-03-2013 4:50pm

Thanks :pac: I'll try the pre's i have first - if they don't work I'll try building one

Fuzzy Clam · 15-03-2013 5:40pm

TroutMask wrote: »

Hmm, and my car has medium-sized wheels :pac:

What does that mean

Of course it will work if the impedances match. Unless you know better?

I would leave off trying to build your own pre-amp untill you gain a little more knowledge.

TroutMask · 15-03-2013 6:16pm

Fuzzy Clam wrote: »

What does that mean

Of course it will work if the impedances match. Unless you know better?

Chillax brah. It means that the impedance rating of a cart tells you very little about the type of pre that it likes to see, *apart* from avoiding the obvious gain and rolloff issues caused by incorrect loading. Saying that a cart is 47k is like saying that a speaker is 8 ohms - it is not enough information. I'm not interested in a pre that will just work, I want one that will sound good and compliment the cart - that's why I said 'recommended' in the original post. I can google the impedance. I have not had any luck finding a recommended pre - so I'm posting about it.

Fuzzy Clam wrote: »

I would leave off trying to build your own pre-amp untill you gain a little more knowledge.

(sic)

I have little knowledge of London Decca carts, this is true. I am fully qualified to build preamps and a whole lot more.

Slaphead07 · 15-03-2013 6:41pm

TroutMask wrote: »

Saying that a cart is 47k is like saying that a speaker is 8 ohms .

Well you will want to match the impedance of the cart to the pre-amp. Either a phono stage that is adjustable or (like a Tom Evans) can be matched by the manufacturer would be ideal. Otherwise it will sound harsh, hollow or just plain wrong. Cart's can vary a lot whereas speakers are fairly predictable.

TroutMask · 15-03-2013 6:58pm

i know, that's what i said

Fuzzy Clam · 15-03-2013 7:07pm

TroutMask wrote: »

Chillax brah. It means that the impedance rating of a cart tells you very little about the type of pre that it likes to see, *apart* from avoiding the obvious gain and rolloff issues caused by incorrect loading. Saying that a cart is 47k is like saying that a speaker is 8 ohms - it is not enough information. I'm not interested in a pre that will just work, I want one that will sound good and compliment the cart - that's why I said 'recommended' in the original post. I can google the impedance. I have not had any luck finding a recommended pre - so I'm posting about it.

(sic)

I have little knowledge of London Decca carts, this is true. I am fully qualified to build preamps and a whole lot more.

You asked whether it will work. Of course it will. It's not a black art, whatever some may think. It's simply an electrical connection between cart and amp.
If the impedance matches (and it's not the same issue as with loudspeakers because effiency comes into play), then it will load correctly. Perhaps you could explain why it wouldn't.
You want a Pre that compliments the cart. In what way? You say the cart is "classical" in sound. So do you want a Pre that gives a true representation or one thats adds some "colour2 to the sound for your metal records?

In an ideal world, it shouldn't make any difference what pre you use but some "colour" the sound in different ways to others. Also the RIAA curve "should" be the same in all amps but i guess different designs give different results.
I doubt that there is one recomended Pre for that cart.
Ultimately, what sounds good depends on you.
Some people prefer certain combinations of cart and pre and main and speakers over others.

I'm sure you could build a Pre for it but the fact you hadn't even tried the Pre that you already have doesn't inspire confidence

Fuzzy Clam · 15-03-2013 7:13pm

TroutMask wrote: »

i know, that's what i said

That's not what you said.

Saying that a cart is 47k is like saying that a speaker is 8 ohms - it is not enough information

TroutMask · 15-03-2013 7:22pm

I think you're very presumptuous and seem to like passing snide comments. I have not tried the pres I own because I'm 1000 miles away from them right now.

and

it is what is said: "*apart* from avoiding the obvious gain and rolloff issues caused by incorrect loading."

Fuzzy Clam · 15-03-2013 7:34pm

TroutMask wrote: »

I think you're very presumptuous and seem to like passing snide comments. I have not tried the pres I own because I'm 1000 miles away from them right now.

and

it is what is said: "*apart* from avoiding the obvious gain and rolloff issues caused by incorrect loading."

I'll try again. The loading is 47K. If the impedance matches, there is no incorrect loading. If there is, please explain.

Slaphead07 · 15-03-2013 8:02pm

TroutMask wrote: »

i know, that's what i said

Actually it's not but I'm done here. I suspect Fuzzy and myself have had enough 'tude.

TroutMask · 15-03-2013 8:58pm

@Fuzzy Clam
My stance is that there is more to the pre - cart equation than impedance matching, though this is important. Unlike yourself, I do believe that component matching is a black art. BTW I never advocated impedance mismatching - and you seem to suggest that I did. What I was saying was that the impedance is printed on the box that the cart comes in so that you can easily match it to a pre. Apart from that, it's a number that doesn't tell you very much. Like the impedance of a speaker, e.g., a B&W 8 ohm speaker and a Lowther 8 ohm speaker both carry the label '8 ohms'. One will sound amazing with a SET amp (or, say, a low power Class A power pentode amp) and one will sound terrible. Why? Because there are numerous other factors involved: the sensitivity of the driver; the Thiele-Smalle parameters; the cone material etc etc. Likewise with carts - nothing we don't already know, I'm sure.

@Slaphead07
sorry about any 'tude - either real or perceived. I'm appreciative of your links to the other forums (HiFiwigwam looks especially good) and always sensitive to the need for impedance matching at all times. Which is why I said: "*apart* from avoiding the obvious gain and rolloff issues caused by incorrect loading."

Which is the same thing you said, albeit more prosaically, when you described the sonic effects of impedance mismatch: "Otherwise it will sound harsh, hollow or just plain wrong." In any event, no offense intended.

Fuzzy Clam · 15-03-2013 10:28pm

TroutMask wrote: »

@Fuzzy Clam
My stance is that there is more to the pre - cart equation than impedance matching, though this is important. Unlike yourself, I do believe that component matching is a black art. BTW I never advocated impedance mismatching - and you seem to suggest that I did. What I was saying was that the impedance is printed on the box that the cart comes in so that you can easily match it to a pre. Apart from that, it's a number that doesn't tell you very much. Like the impedance of a speaker, e.g., a B&W 8 ohm speaker and a Lowther 8 ohm speaker both carry the label '8 ohms'. One will sound amazing with a SET amp (or, say, a low power Class A power pentode amp) and one will sound terrible. Why? Because there are numerous other factors involved: the sensitivity of the driver; the Thiele-Smalle parameters; the cone material etc etc. Likewise with carts - nothing we don't already know, I'm sure.

Ok. slight confusion here. I wasn't suggesting that you advocated mismatching. Quite the opposite. What i did say was that i don't think you need the transformers and, thus, any roll-off etc is not going to be due to matching issues.
Anyway, regards the "black art;)", for sure some carts are going to sound a lot better when "matched" properly to a pre-amp. By "matched", I don't mean impedance matching but rather a pre-amp that compensates for the characteristics of a particular cart.
But it's not a black art, it's electronics. I don't think you can apply the loudspeaker argument here though.

You could also try Vinylengine.com.

Good luck with it and i hope it sounds amazing when you have it set up.

TroutMask · 15-03-2013 10:37pm

Great stuff, thanks! Yeh the traffos i keep around for MC s like my Denon DL 103. I have a knackered Van den Huul that might like 'em too when it's retipped. The Prism has an MC input too. But i know i won't need them for the Decca. I think i'll start with the CJ when i get back and see how that works. Will post when i have a succesful setup

London Decca Super Gold cartridge

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