Step Up Transformer options/advice for MC Blue Point no.2 cart

[seaneee]

Hey all.

Looking for some advice to give my Blue Point no.2 a little boost. I'm running it through a Luxman SQ38Ds tube amp — the one without the internal transformer.

Even though the amp is technically supposed to handle MC carts, it's a little on the quiet side. So looking for some options. Would this be a good scenario for a step up or something as simple as a phono stage?

Just as an FYI, both phono inputs on the amp are 4mV.

This is getting into "over my head territory," so any help would be great.

 

[4-2-7]

I would look at getting a Head Amp, like a SUT it's used between your cartridge and built in RIAA phono stage. The difference being in most cases the head amp is more versatile with adjustable gain and loading.

Look into what the Rothwell Audio Headspace can provide you.

http://www.rothwellaudioproducts.co.uk/html/headspace_mc_headamp.html

And he's a member here also @rothwellaudio

 

[Balifly]

Hey all.

Looking for some advice to give my Blue Point no.2 a little boost. I'm running it through a Luxman SQ38Ds tube amp — the one without the internal transformer.

Even though the amp is technically supposed to handle MC carts, it's a little on the quiet side. So looking for some options. Would this be a good scenario for a step up or something as simple as a phono stage?

Just as an FYI, both phono inputs on the amp are 4mV.

This is getting into "over my head territory," so any help would be great.

The Blue Point no.2 is a homc - high output moving coil cartridge that should be used with a regular mm phono input.

It will run a little quieter than most mm cartridge with the same type of stylus.

You can use any sut that you wish with resulting louder sound and distortion that will not be very pleasing in the long term.

 

[4-2-7]

BTW your thinking is right seaneee, when you effectively boost the gain in your phono staging, you'll effectively boost overall system output when playing records. In other words you'll be able to crank the system up louder playing records and most likely louder than a digital source.

 

[4-2-7]

The Blue Point no.2 is a homc - high output moving coil cartridge that should be used with a regular mm phono input.

It will run a little quieter than most mm cartridge with the same type of stylus.

You can use any sut that you wish with resulting louder sound and distortion that will not be very pleasing in the long term.

Just because one boost gain in the phono staging doesn't equal distortion. Yes one can push things to far but it would take a lot to do that. All systems are different and one size doesn't fit all.

 

[Balifly]

Just because one boost gain in the phono staging doesn't equal distortion. Yes one can push things to far but it would take a lot to do that. All systems are different and one size doesn't fit all.

I differ to your more knowledgeable use of sut sir.

 

[seaneee]

Thanks for the info. The Rothwell seems to fit the bill.

The Luxman has two phono inputs. I did a side by side with the aforementioned blue point and a Nagaoka MC cart. The volume levels were obviously different, but so much so that I feel like the Sumiko needs a little boost.

 

[4-2-7]

Thanks for the info. The Rothwell seems to fit the bill.

The Luxman has two phono inputs. I did a side by side with the aforementioned blue point and a Nagaoka MC cart. The volume levels were obviously different, but so much so that I feel like the Sumiko needs a little boost.

I have Sumiko HOMC cartridges and I use them though a SOTA head amp into a MM & MC RIAA built in phono stage. I us the 18 db gain in the MC input, and the 27db gain in the MM input. It works, and until you try this kind of stuff in your own system you will not know what works best for you. Every once in a while I'll get a hot record that will star distorting, I general change the loading for a quick fix on that record. But thats the trick part of adding a head amp, you'll have versatility and adjustability.

I differ to your more knowledgeable use of sut sir.

I don't know about that, in fact I don't know much about SUT at all. I'v had my cartridges and staging setup like this for about 5 years now. I gave this recommendations or I was saying how it's setup before in a thread. Even Rothwell hit me with that distortion comments with running a HOMC with a head amp. I told him I don't have distortion and I can hear clearly. Well he soon ended up making this headspace with a wide range of gain settings so it can be used with anything. It's a great idea and it's needed.

SOTA head amp designed by John Curl, even states in it's paper work, for High and Low carts.

 

[rothwellaudio]

The Blue Point No. 2 is a high output MC cartridge with 2.5mV output. Although it's "high output" for a moving coil it's still a bit on the low side compared to moving magnet so you can afford to boost it a little bit without overloading the phonostage. Most step-up transformers would be totally unsuitable because their turns ratios are far too high. However, I offer a step-up transformer with a low turns ratio specially designed to give HOMCs a bit of a lift. Using it will boost the cartridge's output up to healthy MM levels - round about 7mV as opposed to the 2.5mV you have now.
http://www.rothwellaudioproducts.co.uk/html/sut_for_homc.html

Another option is to use a headamp. A headamp is an amplifier that goes between the cartridge and phonostage and is usually used to bring low output moving coils up to moving magnet levels, much like a step-up transformer, but uses an amplifier rather than a transformer to do it.
Again, most headamps would be totally unsuitable for use with a high output MC cartridge but the headamp I make has a low gain, high impedance setting specifically designed to give HOMCs a small boost. You'll get about the same amount of boost as you would with MC1-H step-up transformer mentioned above, but you will also have the option of using it with LOMCs at some point in the future if you want to.
http://www.rothwellaudioproducts.co.uk/html/headspace_mc_headamp.html

Both units are available in the USA from Brit Audio and Needle Doctor.
http://www.britaudio.com/
https://www.needledoctor.com/

Look into what the Rothwell Audio Headspace can provide you.
http://www.rothwellaudioproducts.co.uk/html/headspace_mc_headamp.html

Thanks for the mention - much appreciated

 

[JFRACE]

1 other way is to get a sut with a lower gain and use it that way, something maybe around a 1 to 7 ratio. That may be a viable option if you don't go with the above mentioned recommendations.

 

[rothwellaudio]

1 other way is to get a sut with a lower gain and use it that way, something maybe around a 1 to 7 ratio. That may be a viable option if you don't go with the above mentioned recommendations.

I did mention the possibility of using a low ratio step-up transformer but 1:7 is still too high to be ideal. The MC1-H mentioned above has a ratio of 1:3

 

[sqlsavior]

Or, if you have an active line stage with gain, as seems to be the case, you could simply attenuate it less (i.e. - turn the volume knob clockwise).

 

[seaneee]

@rothwellaudio Thanks for the info. Do you have a recommendation between the two? I know the final result is more or less the same, but is there an advantage to a SUT over a head amp (or vice versa).

 

[Blue Shadow]

Although many here talk about an sut being the better choice, the two rothwell products, I might pic the head amp as it has the adjustments to be the right unit for many different cartridges whereas the HOMC SUT is more specifically designed for an HOMC. This may well make it a better sounding unit but how much better, IDK.

The 2.5mV output of the cartridge is going into an amp that would like to see 4.0mV minimum to achieve full output, no wonder it is a little on the quiet side.

 

[4-2-7]

Thanks for the info. Do you have a recommendation between the two? I know the final result is more or less the same, but is there an advantage to a SUT over a head amp (or vice versa).

I would say the advantage would go to a head amp for it's adjustability and versatility. It will be able to be used for almost any cartridge you can buy and be used for many years to come.

I like to try and use stand alone RIAA Phone Stages, Phono Head Amp from the hight of Vinyl playback performance. I feel back then every stereo setup and everyone was playing records. People back then had a reference point as to what sounded good when it came to records. Manufacturers had to build head amps, phono stages and SUTs that sounded better than what came in a receiver, preamp or integrate amp.

However most MC cartridges back then where low output and MM carts. My SOTA Head Amps are from this time and have low enough gain to work in my system, but take a long time to find.

The Rothwell headspace is something he designed not long ago and is setup for todays world. This head amp will work with far more cartridges and systems today than anything else I have ever seen.

I personally don't think you will be disappointed in the headspace for your application in sound quality or function.

 

[rothwellaudio]

@rothwellaudio Thanks for the info. Do you have a recommendation between the two? I know the final result is more or less the same, but is there an advantage to a SUT over a head amp (or vice versa).

...I might pic the head amp as it has the adjustments to be the right unit for many different cartridges whereas the HOMC SUT is more specifically designed for an HOMC.

I would say the advantage would go to a head amp for it's adjustability and versatility. It will be able to be used for almost any cartridge you can buy and be used for many years to come.

I agree with the two posts above - the Headspace is more versatile and could be used in future with low output moving coils. The MC1-H (transformer) is more of a one trick pony.
From a pure sound quality point of view I'm not sure there's much to choose between the two. The headamp sounds a bit more "hi-fi" and has a bit more slam and punch. The transformer is perhaps a bit more polite.

 

[rothwellaudio]

BTW, if the specs I found here are correct...
http://www.thevintageknob.org/luxman-SQ38D.html
... the two phono inputs are different. Phono 2 has 4mV sensitivity where as phono 1 has 0.15mV sensitivity. However, maybe your model is different as there seems to have been several versions. Anyway, since 2.5mV is only 4dB less than 4mV, the cartridge shouldn't be unduly quiet. Maybe it's worth trying the cartridge into both inputs to see if there's any difference, if you haven't done so already.

 

[4-2-7]

... the two phono inputs are different. Phono 2 has 4mV sensitivity where as phono 1 has 0.15mV sensitivity. However, maybe your model is different as there seems to have been several versions.

Wow good call and strange they are not externally marked or the OP didn't see it.

I'd still get a head amp, this difference in the two phono inputs will give more choices on top of it.

 

[Blue Shadow]

The SQ38D was available with and without the built in step up transformers and the OP has the one without these so his phono input sensitivity would be 4mV for both phono inputs...based on internet searching. I'm always up for learning more about Luxman gear.

These amps were the SQ38D with the transformers and the SD38Ds without the transformers and a full ¥4000 cheaper back in 1965. That is a dozen dollars at the 360:1 exchange rate.