re: Audiophile/Vinyl Thread - Post Pics, Advice, Questions, Setups, etc.

Just needed to hear this.

And that’s a dude that could write a song.

Pre-game



Coltrane - “Ballads”
Speakers Corner reissue 2003

It’s a rainy blue note kind of evening...



Grant Green - “Idle Moments”
Music Matters 33 Reissue

I recently made a slight change to the second system. I added a Bob’s Devices Step-Up Transformer.

What is a step-up transformer?

Typically, an older preamp/integrated amp (or a less expensive modern one) only has inputs for a MM phono cartridge, not one for MC. The main difference is a MC (moving coil) cartridge has a very low output voltage range (around 0.2mV—0.9mV) as compared to a MM (moving Magnet) whose typical output voltage range is higher (around 1.0mV—3.0mV).

So, if you try to run a modern, costlier MC cartridge into a MM input, you will get a very, very low volume (unusable). The solution is to add a step-up transformer in between the cartridge and the phono preamp. This will allow you to run an MC cart into a MM phono preamp section.

On the Denon turntable, I am using a Denon 103R cart, which is actually a MC, very low output cartridge (0.25mV). Although the McIntosh c500 preamp has both MM and MC phono inputs, it was lacking a bit. So I decided to add Bob’s Devices step-up transformer, and use the MM input instead of the MC input. It basically adds about 26dB of gain to the output of the cartridge, boosting it up so it can run into a MM stage.

I now set the capacitance of the MM stage “wide open” at 47k ohms, instead of running it into the MC stage that had a resistive loading set to 500 ohms.

In short, it opened the cartridge up a great deal and is a hell of a lot more dynamic and has a better low end.


Sorry to bore you all...

quote:

---

They just re issued this on 3 X 10" vinyl.

---

that’s the one I just picked up! Cut at Abbey Road from original tapes. I could never find out where it was pressed. However, the copy I received sounds fantastic and is dead quiet. Highly recommend.

I will say that I hate the layout for it. Because the second lp is annoying to get out of the middle sleeve. Also all 3 records come in a paper sleeve, so I purchased new inner sleeves for 10”. But sound quality is fantastic!

The 103R is a very low output cart—0.25mV...(and if memory serves me right, a low internal impedance of 14ohms—unlike the non-R 103 version—which I believe is around 40 ohms)—the Mani has a few gain settings which is nice. I would chose the one that gives an overall output that matches close to the other inputs (CD, aux)...if it is too loud or sounds saturated, drop it down a notch and listen again. That is a nice feature to have.

Most often I see the 103R loaded at 1000 ohms. I have, however, read where some are loaded at 100 ohms—depends on the gear and the ears.

I listened at 500 ohms for a week or so, then moved to 1000 ohms and that was the winner. The best way to listen is not to do an A/B immediate back and forth switch, but to listen one way for an extended period, maybe a week, then change and listen again.

Mine sounded pretty good at 1000 ohms into the MC input, however, I was having to compensate for the very low output of the cart by turning the volume knob to the right—no problem—unless you are driving the worlds most inefficient loudspeaker—Magneplanar. When I listen at higher levels, they are eating every last watt of the 500w monos, and when you add the low output of the cart, well, I needed another bump in gain—hence the Bob’s Devices step-up transformer. It also has a high and low gain selector.

You have an advantage here in that the Zu Audio is on the opposite end of the spectrum from the Maggie’s when it comes to efficiency, so you shouldn’t have a “running out of power” issue.

As to what the advantages are between one load setting and another...sound. The low end may become a little “snappier” with one load setting, or the highs may sound a bit “veiled” with another. There is a happy medium among the six or so settings. Some of the really high end phono stages allow custom load settings that can be built in to an exact load while others provide 20-30 choices as opposed to the 5 or 6 you customarily find in sub $3k phono stages.

Go look at the Simaudio Evolution 810LP phono stage on their site for an example of a myriad of options of a higher end one ($15k).

A decent SUT isn’t cheap. Bob’s Devices is around $1200. I don’t think you will have an issue with gain, however.

A good, quiet phono stage with numerous MM & MC settings would be a better money spend, IMO. The Lehmann is really hard to beat for $500...are there others out there?—sure, but I can speak on behalf of the Black Cube as I used one for a while running into a McIntosh c2300 preamp for a couple years and it was excellent.it is dead quiet and detailed on the clinical side (no warm and fuzzy tube sound here).

I would like to try Paradigm’s new JC-3 Jr.—a lesser expensive, little brother to the JC-3, which is also hard to beat at $3k.

I got a SUT because I fell into a little niche where the phono stage I am using is built into a preamp and I needed to run a MC into a MM input for gain reasons. The phono stage in the Mac is excellent, however of the 2 options to solve my issue (either get an external phono stage equal to or better than the Mac—which would be $3k+, or get a SUT for a good bit less and still use the great phono stage in the Mac), the SUT was not only less expensive, but also gave me some flexibility. And now I have a SUT Incase I ever want to run a MC cart into one of the older Marantz, Sony, McIntosh, Fischer, or Luxman receivers/integrates I fix up, as most only have a MM stage.

I found the following and this fella says it better and more concise than I would. It is a lot of info packed few paragraphs...

That word "load" causing confusion again.
The problem is the ambiguous way the word is often used. Cartridges have a source impedance, also known as an internal impedance, which is made up of the resistance and inductance of the coils' windings. Most MM cartridges have an internal impedance of roughly 1k and a few hundred millihenries. Most MC cartridges have an internal impedance of about 10 ohms with negligible inductance.
The load impedance is something different. That's the impedance that the cartridge is fed into. A rule-of-thumb for audio equipment in general is that the load impedance should be 10 times the internal impedance, or more, to maximise the signal transfer. Sometimes a specific load is recommended.

For a typical MC cartridge with 10 ohm source impedance, a 100 ohm load satisfies the "load should be 10x source impedance" requirement, and that is the load often seen on MC phonostages.
However, the Denon 103R has a higher than average source impedance of 40 ohms. It requires a load impedance of 400 ohms to satisfy the "load should be 10x source impedance" requirement. Increasing the load impedance beyond that makes less and less of a difference because once you get past 400 ohms the load impedance is already much bigger the source impedance.

The step-up transformer is a bit of a red herring which only adds to the confusion. It makes no difference to the cartridge whether the load it is driving is a resistor at the input of a solid state phonostage or the primary winding of a step-up transformer. Either way, 100 ohms is 100 ohms. All too often step-up transformers are ambiguously stated as being, for example, "40 ohms". What does that mean? Does it mean its input impedance is 40 ohms? Or does it mean it is intended to work with 40 ohm source impedances? It usually means the latter, in which case its input impedance is not 40 ohms.

As for your performance test graph, that's the performance when the cartridge is fed into a 47k load. The performance will be pretty much the same for any load that is a lot bigger than the source impedance - ie more than ten times the source impedance. The performance will suffer as the load impedance drops down to values approaching the source impedance of, in this case, 40 ohms