J E Sugden Masterclass LA-4 line preamplifier Specifications

Sidebar 1: Specifications

Description: Solid-state stereo preamplifier with remote control. Inputs: 4 single-ended (RCA), 1 balanced (XLR), 1 single-ended tape (RCA). Outputs: 2 single-ended line-level (RCA), 1 balanced line-level (XLR), 1 tape (RCA). Input impedance: 50k ohms (single-ended), 25k ohms (balanced). Output impedance: 600 ohms (single-ended, balanced). Input sensitivity: 100mV for 1V output. Maximum output (to clip): 10V. Bandwidth: 6Hz–300kHz. Frequency response at 1V output: 15Hz–30kHz, ±0.1dB. Stereo separation (weighted): >90dB. Distortion (1V output): 0.006% at 1kHz.
Dimensions: 16.9" (430mm) W by 3" (75mm) H by 13.8" (350mm) D. Shipping weight: 15.4 lb (7kg).
Finishes: Black, Silver; one of 16 custom colors, add $250.
Serial number of unit reviewed: MASTERCLASS-LA-4-0418.
Price: $3750. Approximate number of dealers: 12. Warranty (nontransferable): 5 years, workmanship; 2 years, non-Sugden parts; 1 year, labor, non-Sugden parts replacement.
Manufacturer: J E Sugden & Co. Ltd., Valley Works, Station Lane, Heckmondwike, West Yorkshire WF16 0NF, England, UK. Tel: +44 (0)1924-404088. Web: www.sugdenaudio.com. US distributor: Tone Imports. Web: www.toneimports.com.

J E Sugden & Co. Ltd.
US distributor: Tone Imports

tonykaz's picture

Sugden is one of those Brit Companys I never got round owning any of, dammit, I just plain ran out of Time before my Audio Business World stopped turning.

Still, I've been curious about the Sugden A21 and the entire Range.

If I was still trying to do HighEnd Audio I'd certainly like a Corner of my Shops featuring the Sugden Range. I'd even do all those Colors.

Sugden always seemed like a PS Audio kind of Company that never made it to the USA or anyplace I've ever been.

The Product Looks substantial. If I happened upon the Sugden people at one of the Shows, I would've bought some "on the Spot".

I wonder if it's at good as it looks, hmm. I hope to find out, one day.


Tony in Michigan

georgehifi's picture

Strange distortion measurements differences.

Balanced transformers? could it be saturation with higher level if it's got them??

Cheers George

monetschemist's picture

... or what? Or is it just me? In any case, wow, kudos to Sugden for making something I want to go and find and touch.

I love the GH quote from RD in the last paragraph. I've been listening to fine music, often intensely, on decent or better equipment, for more than 40 years now. I've never quite got to the point where I find myself wishing I had kept component XYZ because I loved the sound so much; but if I don't understand, I sympathize at least!

Ortofan's picture

... the best choice, according to Doug Self.

tonykaz's picture

Thick shielding for the Power Transformer.

Construction looks substantial.

Sugden needs an Up-Dated Photo Album of their Manufacturing .

Dam nice looking Gear.

Tony in Michigan

Ortofan's picture

... electrolytic capacitors from - Samwha.

Bogolu Haranath's picture

JA2 used Revel Ultima Salon2 for this review ....... One of the best loudspeaker designs ....... Has been in continuous production since 2008 ........ Those speakers would be a great reviewing tool for associated equipment :-) .........

tonykaz's picture

Yea, I think his are Vintage, not the Asian versions.

Bob Katz sold his Ultima Revels ( not to me, I tried to buy his but was too late ). Bob switched to DynAudio.

Seems that JA1 & JA2 are not! Better get it right, or else....

1) JA1 is JA,

2) JA2 is JCA

I hoping to know more about Sugden, this just might ( or might just ? ) be a rare "Everyman's" Brand of Class A Recommended Components for us "Poor Man's Audiophile" types. ( or "Stereophile types" if Canadian ).

Maybe our intrepid Robert Scryer meets Sugden's Canadian Rep. from BC and works out an A21 Review Sample to compliment the already positive appraisals from Stereophile's Management Staffers. Fingers Crossed !!

Tony in Michigan

ok's picture

effectively dealing with basic philosophical as well as practical issues of testing methodology. The “bypass mode” cannot literally be what its name might suggest – since there still is a "source" output stage with its own impedance/EQ characteristics not always compatible with the main amp's input and therefore a half-baked preamp in potential need of revision (what kind of exactly?) – but necessary nevertheless for the evaluation process. Any part of a given circuit can be omitted (as is actually the case with SET, OTL, zero-feedback, DC-coupled etc designes) as long as it allows for a functional output, more often than not in order to highlight certain kind of "detail" at the expense of another; it has even happened to me once to suddenly start “hearing things I had never heard before” as an unexpected result of some gross hardware malfunction..

jmsent's picture

It's hard to understand why Sugden would make a fully balanced preamp; i.e., 4 identical gain channels from input to output, when they only have one balanced input. What would be the point? A full balanced design is twice as complex as a single ended one but gives you literally nothing advantageous over a single ended design without being fed by a balanced signal. I'm also skeptical that the preamp even operates this way. From the posted photo, the volume control appears to be an ALPS dual gang motorized potentiometer. But for full balanced operation, you need 4 gangs, not two, and a control for that would be physically much larger. So unless they've created some novel approach to fully balanced operation, I'm inclined to believe that there's balanced to signal ended conversion going on at the balanced input, and single ended to balanced conversion going on at the outputs. BTW, many preamps with balanced inputs and outputs operate in this fashion.

klosterman's picture

This review for me was a primer on a variety of topics. Read it 3x. My fave stereophile of all time; going back many moons.