Phonostage questions - I need help....

[Wakefield Turntables]

Guys,

I need to get my head around a few things and I wondered if you can help. I'm looking at replacing my cartridge.

1. But could anyone explain what the relevance of "gain" i.e. the Whest REF V phonostage has 53db of gain, how would this help me pick a matching MC cartridge? What are the implications of lower or higher levels of gain ?

2. My current Masterclass phonostage has +/- 0.3db 30Hz to 30kHz, my current cartridge which is a AT OC9ML/II has a frequency response of 15-50,000 Hz, does mean that my phonstage is not capable of outputting the
lower and higher frequency response of my cartridge? Would it be better to get a phonostage to match your cartridge frequency response. ?

Lots of questions, probably basic. Sorry for my ignorance:o

thanks in advance.

[Reid Malenfant]

Hi Andrew, with 53Db of gain your phonostage multiplies the input by 446.7, so if you happen to be using a cartridge that outputs 0.3mV then the output from the phono stage will be approximately 446.7 x 0.3mV or 0.134V...

That sounds kind of low to me, so if we take an average moving magnet cartridge of say 3mV the output would be 1.34V which looks a bit better in my eyes ;)

It looks like your phono stage may well be optimised for high output MC or MM cartriges, though admittedly line level on some pre amps can be 200mV or so...

You sure you can't adjust the gain? Maybe there is some small DIL switches internally?

As for the frequency response I wouldn't worry as you quoted +/- 0.3DB which means the -3Db point will be much lower & higher so it actually has a wider bandwidth than you think :)

[Wakefield Turntables]

Reid,

I have the Sugden Masterclass PA4 phonostage, I've been looking around the net for the amount of gain its supposed to push out but I cant find it. I've got a better understanding of gain and relevancy to MC selection. I was looking at getting the Lyra Helikon SL as this has a much better matching output voltage of 0.22mv which matches my phonostage input sensitivity better which is 0.15mv. I use a AT OC9ML/II with output voltage of 0.4mv. My problem is now figuring out if the Masterclass phonostage has the 60db of gain needed for the Lyra Helikon SL, i would presume it has but embarrasingly I cant find the gain levels for the bloody thing :doh: Thanks for your help so far!

Secondly you mention line level of the pre-amp does this need to match the similar output for the phonostage?

[Reid Malenfant]

Secondly you mention line level of the pre-amp does this need to match the similar output for the phonostage?
Well I think most pre amps tend to have a line level input of around 0.5V or so? Older stuff appears to be lower at 200mV, though they all differ if the truth be known ;)

All it means is that if you happened to put a lower input into the pre amp than standard, you'd have to turn the volume up higher than you would with a device that gave the correct line level to get the same volume in the room :)

It's as simple as that at the end of the day :eyebrows:


Have you tried Sugdens website or looked for a review which should give specs?

[John]

You ATC preamp should be adding some gain to this as well

[Wakefield Turntables]

Reid,





Have you tried Sugdens website or looked for a review which should give specs?

The nearest I could find was something called "signal to noise" -70db. Could this be it??? Thanks for your other explanation regards line level from the pre-amp.

John,

I think you are probably correct as i can control gain from the pre-amp which does make things quiter. Personally that button is never pressed :lolsign: as i pefer to listen to very loud prog and thrash metal :rock::fingers::fingers:

[DSJR]

Doesn't the SCA-2 have an optional phono stage (I think I have the correct one, but mine was the first and rather expensive model) Mine was internally configurable for MM or MC cartridges and performed very well, the limitations, if there were any, were in the line buffers.

[Reid Malenfant]

Signal to noise isn't the gain unfortunately, give us a link to what you were looking at & I'll have a look myself, there may be some subtle info on there ;)

Signal to noise is the background level of noise + distortion etc relative to the output level, 70Db isn't too bad at all.

[Wakefield Turntables]

Doesn't the SCA-2 have an optional phono stage (I think I have the correct one, but mine was the first and rather expensive model) Mine was internally configurable for MM or MC cartridges and performed very well, the limitations, if there were any, were in the line buffers.

Yes mine has a phonostage but i hate it and prefer the sugden! I'd have it removed if I thought it would improve the pre-amp.


Signal to noise isn't the gain unfortunately, give us a link to what you were looking at & I'll have a look myself, there may be some subtle info on there ;)

Signal to noise is the background level of noise + distortion etc relative to the output level, 70Db isn't too bad at all.

Reid,

http://www.sugdenaudio.com/masterclass.htm

You can download a pdf from a column on the upper right of the webpage but i dont think you'll find anything new :(

[DSJR]

The built in phono stage wasn't bad IMO, so hopefully it's just a matching issue?

[John]

Reid,


Personally that button is never pressed :lolsign: as i pefer to listen to very loud prog and thrash metal :rock::fingers::fingers:
A man after my own heart:cool:

[Reid Malenfant]

Reid,

http://www.sugdenaudio.com/masterclass.htm

You can download a pdf from a column on the upper right of the webpage but i dont think you'll find anything new :(
It's Mark by the way :eyebrows:

If you are talking about the PA4 phono stage I have the figures for you :ner:

MM gain = 40.25Db
MC gain = 67.6Db

Now who says subtle info isn't handy ;)

[Wakefield Turntables]

It's Mark by the way :eyebrows:

If you are talking about the PA4 phono stage I have the figures for you :ner:

MM gain = 40.25Db
MC gain = 67.6Db

Now who says subtle info isn't handy ;)

Mark (just going by your screen moniker of Reid ;)) Yep its the PA4. Big big thanks for your hard work. I think I need about 64db of gain according to a quick calculation I did on http://kabusa.com/frameset.htm?/phonpre.htm, so it looks like I have a couple of db to spare and the cart I want is compatible with my phonostage :eyebrows:

[Reid Malenfant]

Yes, it'll be ok by the look of things :) No hard work Andrew, I just looked at the input & output voltage figures & converted to Db gain ;)

You might need to run the volume control a tad lower, but not a lot (to match other kit). Seeing as you don't know what they output & the level recorded at it's all quite unimportant :eyebrows:

It'll do the trick is all you need to know :cool: