How do I raise the output of an already high output MC cartridge

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Posted on July 12, 2012 at 04:25:22

dmarkh
Audiophile

Posts: 4
Location: Melbourne Florida
Joined: July 12, 2012

I'm running a Pioneer Spec system. Spec-1/Spec-4 with a PL-630 TT fitted with a Benz MC silver cartridge. The cartridge output is 2.0mv. The Spec-1 phono inputs where designed for MM cartridges which, if I remember correctly, were normally between 4-8 mv. The phono-1 input on the Spec-1 pre-amp is spec'd at 2.5mv. The phono-2 is spec'd from 2.5mv - 10mv. It has an attenuator dial.

With this setup, using either phono-1 or phono-2, to listen loudly, requires the volume to be almost %80 max. In fact it will not go as loud as I would like it to wide open. Is there a K&K product that I could use between the TT and the Spec-1 phono-2 inputs that could give me more reasonable levels such that the TT volumes were more like the rest of the input volumes? Again the MC cartridge is a High-output at 2.0mv.

Thanks
Mark

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RE: How do I raise the output of an already high output MC cartridge

KevinC

04:44:10 07/12/12

4

RE: How do I raise the output of an already high output MC cartridge

dmarkh

05:02:15 07/12/12

3

RE: How do I raise the output of an already high output MC cartridge

KevinC

06:12:21 07/12/12

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RE: How do I raise the output of an already high output MC cartridge

KevinC

04:44:10 07/12/12

4

RE: How do I raise the output of an already high output MC cartridge

dmarkh

05:02:15 07/12/12

3

RE: How do I raise the output of an already high output MC cartridge

KevinC

06:12:21 07/12/12

RE: How do I raise the output of an already high output MC cartridge

dmarkh

06:39:42 07/12/12

RE: How do I raise the output of an already high output MC cartridge

dmarkh

11:39:57 07/12/12

RE: How do I raise the output of an already high output MC cartridge, posted on July 12, 2012 at 04:44:10

KevinC
Manufacturer

Posts: 2535
Joined: April 19, 2001

Lundahl doesn't make an MC input transformer that is really well-matched to your application. The lowest step-up ratio transformer that is suitable is the LL9206 with 1:5, instead of 1:2. However, I suspect that the LL1527 microphone input transformer connected for 1:2 operation will work well given that nominal microphone source impedances are not much different from your cartridge's. You should realize that that with this transformer in between the cartridge and the phono preamp, cartridge will "see" the phono preamp input impedance load as one-fourth of it's current value (probably 47K). I don't think that's a problem, but it needs mentioning.

Kevin Carter
K&K Audio
www.kandkaudio.com

RE: How do I raise the output of an already high output MC cartridge, posted on July 12, 2012 at 05:02:15
dmarkh Audiophile Posts: 4 Location: Melbourne Florida Joined: July 12, 2012	So the LL9206 would give me 10mv? Could I not use this on the phono-2 input and just turn the phono-2 attenuator knob on the Spec-1 preamp down about halfway or so?

RE: How do I raise the output of an already high output MC cartridge, posted on July 12, 2012 at 06:12:21
KevinC Manufacturer Posts: 2535 Joined: April 19, 2001	The LL9206 will give you about 12.5mV. That is outside the specified range that you gave for the input. Since I don't know where the attenuator is in the circuit and what the consequences of going above 10mV are, I couldn't recommend the LL9206. Kevin Carter K&K Audio www.kandkaudio.com

RE: How do I raise the output of an already high output MC cartridge, posted on July 12, 2012 at 06:39:42
dmarkh Audiophile Posts: 4 Location: Melbourne Florida Joined: July 12, 2012	Thank you very much for your help. I also don't know where the attenuator is in the circuit and what the consequences of going above 10mV are. I think I can find out though. I will consider both of these as options that I need to investigate further. Thanks and Regards Mark

RE: How do I raise the output of an already high output MC cartridge, posted on July 12, 2012 at 11:39:57

dmarkh
Audiophile

Posts: 4
Location: Melbourne Florida
Joined: July 12, 2012

Hi Kevin, I have verified, at least to my satisfaction, that 12.5mv coming to the phono-2 stage will not hurt anything. The levels given in the service manual are minimums. Even the range on the phono-2 input. If the knob is turned all the way down the min recommended input is 10mv. If it's turned all the way up, the minimum recommended input is 2.5mv. The service manual says the phono-1 overload is 500mv (1000Hz) and phono-2 overload is 500mv to 1000mv (1000Hz). Does this make sense? If I were to do this with the LL9206's what would be my next step? Send you an email?

Regards
Mark

K&K Audio / Lundahl Transformers

How do I raise the output of an already high output MC cartridge

50.89.247.146