SUT - electrical theory and practical experience


Some vinyl users use a SUT to enhance the signal of the MC cartridge so that it can be used in the MM input of a phono stage.  Although I don't understand the theory behind it, I realize that a SUT should be matched individually to a particular cartridge, depending on the internal impedance of the MC, among other things.  

Assuming an appropriately / ideally matched SUT and MC, What are the inherent advantages or disadvantages of inserting a SUT after the MC in the audio chain?  Does the SUT theoretically enhance or degrade the sound quality?  What does the SUT actually do to the sound quality? 

Thanks. 

drbond

Here the DL 1000A ( btw, one of the J.Carr vintage cartridge favorities. ):

 

Main features of DL-1000A

■ We challenged the limits of weight reduction and achieved an astounding effective mass of 0.077mg.

The vibration system of the DL-1000A faithfully traces the complex and fine sound grooves, so a new material, New Amorphous Boron Pipe, is used to thoroughly reduce the weight of the vibration system, resulting in an effective mass of 0.077mg. realized. (DL-305 is 0.168mg) In
addition, coupled with light effective mass and well-balanced high compliance, extremely stable tracing is performed not only in the mid-low range, but also in the fine sound grooves in the high range. It is extremely rare to deform the sound groove. As a result, the playback band extends to an unprecedented ultra-wide band of 20Hz to 110kHz.

(1) High rigidity, ultra-thin and lightweight new amorphous boron pipe cantilever

DL-305 and DL-207 use amorphous boron, which is said to be the most ideal cantilever material and has a large specific rigidity. A cantilever with a thickness of 0.3 mm, a thickness of 0.023 mm, and a length of 4 mm is used.

(2) World's smallest micro stylus chip

Reducing the weight of the stylus tip, which is positioned at the forefront, has a great effect when reducing the effective mass seen from the tip of the stylus. It was considered very difficult to make a stylus chip micro, but we have improved our processing technology and accuracy to create a 0.06 mm square micro chip. (Approximately 1/2 of DL-303/305) The
shape is a special elliptical needle that has been precision machined.

(3) Uses a small cross-shaped winding frame and extra-fine copper wire

The cross-shaped winding frame can reduce the mass, and the left and right channel generating coils can be wound independently and symmetrically, and the dynamic balance during vibration is good, the sensitivity difference between the left and right channels is small, and uniform characteristics can be obtained. has two major advantages. The well-balanced generator coil uses ultra-fine copper wire, which advances the significant weight reduction of the vibration system.

(4) Like a feather. Stable tracing with record-friendly stylus pressure of 0.8g

The dramatic reduction in effective mass enables well-balanced, high-compliance, and a light stylus force of 0.8g shows sufficient tracing ability, providing stable tracing even for high-level cutting records. We will realize

(5) Flat ultra-wideband reproduction by 2-way damping system

In addition to broadening the bandwidth by reducing the effective mass, coupled with the adoption of DENON's original 2-way damper, flat frequency characteristics up to 110 kHz are realized, and reproduced sound with good energy balance can be obtained.
In addition, good temperature characteristics (small difference in sound quality between cold and warm regions) is another feature of 2-way damping that cannot be overlooked.

■ Powerful power generation structure

A samarium-cobalt magnet (with a magnetic energy product several times that of conventional magnets) is used in order to obtain a compact, lightweight, and strong air-gap magnetic field.
The weight of the cartridge has been reduced to 6g, but reducing the weight of the cartridge has the effect of reducing the effective mass seen from the position of the stylus of the tonearm, and the ability to follow the warp and eccentricity of the record. have a great effect on increasing

■ Emphasis on stylus pressure vs. output voltage characteristics

DENON attaches great importance to stylus pressure vs. output voltage characteristics as one of its basic performances.
The vibration system of the cartridge receives extra changes due to warpage of the record, etc., and the stylus pressure constantly changes. For this reason, if the linearity of the power generation system is poor, the output voltage will fluctuate greatly or be modulated, making it impossible to obtain a clear reproduced sound.
The DL-1000A has excellent linearity in the power generation system, and in combination with its excellent tracing ability, you can always obtain high fidelity and stable reproduced sound.

■ Promoting non-resonance with a strong frame structure

In order to fully demonstrate the performance of the excellent vibration system, we have adopted a strong frame structure that is non-resonant.
The frame, including the powerful magnetic circuit and output terminals, is made of hard resin containing glass fibers and a machined light alloy base.


To amazing tracing ability
World's lightest - effective mass 0.077mg

The effective mass of the vibration system, which has been thoroughly refined and polished, has achieved the lightest weight of all cartridges, 0.077mg. At the same time, the world's largest dynamic compliance of 20 x 10-6 (static 50 x 10-6) cm/dyne is achieved. I just got amazing tracing ability. With this new dimension of tracing ability, you can reach the musical depths of record grooves that you could not reach before, and draw out all the musical information that could not be reproduced in the past.

■ Comparison of sound groove traces

■ DL-1000A output voltage and crosstalk versus frequency characteristics

■ Comparison of frequency characteristics due to temperature change

■ Cartridge case can be used as a cartridge keeper

The DL-1000A is delivered in a velvet-covered case. This case can store 5 cartridges with shells.
The stand on which the DL-1000A is installed can be used as an audio stabilizer after removing the cartridge.


DL-1000A major specifications

  • Power generation method: Moving coil type
  • Output voltage: 0.1mV (1kHz 5cm/sec horizontal direction)
  • Left and right sensitivity difference: within 1dB (1kHz)
  • Right and left separation: 30dB or more (1kHz)
  • Electrical impedance: 33Ω (20kHz or less)
  • Compliance:
    Record reading 20×10-6cm/dyne (100Hz)
    Static reading 50×10-6cm/dyne
  • Transducer effective mass: 0.077mg
  • Needle tip: 0.06 mm square solid diamond special elliptical needle
  • Stylus force: 0.8g±0.1g
  • Reproduction frequency range: 20Hz - 110kHz
  • Compatible load resistance: 100Ω or more (40Ω when using a transformer)
  • Weight: 6.0g  and is an exeptional tracker with its very high compliance over 30cu.
  •  

"" The concern IMO isn't the high end! its how well it goes low. ""

 

with the rigth MM stage design way better that any tube phono stage. You have to listen any of the SUTs I named here.

 

I forgot that I owned the Supex and left it goes due that in those times my knowledge levels were still lower than today. Shame of me for that.

 

R.

In practice my SUT experience was disappointing. I used highly regarded Cinemag transformers with my Lyra Delos cartridge perfectly matched. The sound was energetic and loud but the treble was edgy and grainy.

Using my Sutherland 20/20 fully active without the SUT sounded much better.

SUTS are something you add if you do not want to purchase a good active phono preamp.  My experience.  

Dear @drbond : About quality level performance in SUTs the best regarded/build transformers are: the Hashimoto 7, the Altec 4722 and Tamura TKS83. Lundhall or Jensen are in a lower " league ".

Altec and Tamura are not in production any more, at least to my knowledge. Btw, the gentleaman behind HM-7 is Isao Asakura.

Denon choosed a special custom design Tamura transformers for the AU-1000 ( Denon use the standard Tamura in its AU-340 that I own too and modified too. ) and here what a true music lover and SUT expert said about ( he already tested the Lundhall, Jensen and others. ):

 

" HM-7 sound falls somewhere in between the organically detailed and dynamic TKS83 and the rich and spacious airiness of the classic 4722. "

No one of then are transformers silver wired but are the best of the best in SUTs.

 

Btw, the AU-1000 Tamura transformers are better than the others I named here. The Tamura in the AU-340 is the one reffered by that gentleman full comparisons.

 

R.