COLIN WONFOR: Source of decent linear power supplies?

Dear Colin, Linear power supply sourcing. Hi I am looking for a linear power supply. Either two single or a single with dual outputs I need a input of 240V AC and output of 20V DC 3-4 amps any pointers on where I might source a kit from would be most welcome. Cheers Vellerman Kits; […]

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Step-down transformers with unchanged mains frequency?

Hi Colin, Pls can you help me? Can I safely run a USA spec amp designed for 110v 60Hz in the UK on 240v 50Hz, with a step down transformer (but it will still be 50Hz). So many conflicting views across the web. I think a lot of people believe it can work ok the […]

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COLIN WONFOR: Boutique brand, or mass-market gentlemen?

Hi Colin. First. Congratulations on rising phoenix-like from a difficult time with difficult people! From what I have read my impression is that you are intent on keeping Elsdon Wonfor Audio small; a boutique-brand if you will. However for the sake of conversation, or curiosity or whatever, if you wanted to, could the company be […]

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Colin Wonfor’s Clinic: Amplifier buzz even when power switch is off!

Dear Colin, I need some theories and hopefully answers please. This is a situation, neither I, not anyone who I asked, have encountered before. It is very simple and puzzling at the same time. Here it is: There is a faint buzz coming from the amplifiers, NOT the speakers, barely audible from a few feet […]

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COLIN WONFOR: JLH Class A headphone amp build help needed!

Dear Colin, I’d buy from you but as far as I can see one4audio. don’t make one – or do you or will you? Anyway, I’m planning on building a JLH class A headphone amplifier but am a bit confused regarding the transformer wiring/connection. The pcb requires 15v-0-15v AC power input. I plan on using […]

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The Art of Electronics (Horowitz & Hill) 3rd ed; still the best?

Dear Colin, The Art of Electronics (Horowitz & Hill) 3rd ed… … as DIYers probably already know is now out, only 25 years after the 2nd ed. My copy arrived today. I’m not trained in electronics and make no claim to more than a passing knowledge, but have enjoyed these authors’ style of presentation since […]

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COLIN WONFOR: Marketing as an influence on audiophile design

Hi Colin. To what extent – if any – does marketing influence your designs? It has ….. for a few things. I’ve not really taken much notice of marketing and to be honest, if an audio business is run by money grabbing twits like those I’ve met in the past then … no thanks. I […]

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Colin Wonfor’s Clinic: My meter isn’t going to zero any more on ohm ratings

Dear Colin. My meter isn’t going to zero any more on ohm ratings, and it apparently can’t be calibrated. It’s a fairly low-end Radio Shack autoranging model. I saw that the “what do you need for repairing equipment” on a US thread suggested a Fluke 114 or 115. Is that still the best, or do […]

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What wire for rewiring QUAD power amp please?

Dear Colin, I’ve just picked up a Quad 405 ready for service. When I serviced my previous 405 I used the Dada kit which came with the necessary wire. Can you tell me please what size / gauge wire I should use to replace the existing power wires? Would this be suitable? http://www.rapidonline.com/design-te…0m-reels-62317 or could […]

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Types of resistors for crossovers?

Dear Colin, I have just fitted stock 2R7 Panasonic 0.1% metal film resistors to replace the “green” 2R2 wirewounds in series with the Millennium tweeters in my WD25Tex speakers. I expected a change ( a bit warmer) but was not prepared for such a drastic change – is this due to the 0,5R increase or […]

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COLIN WONFOR: Do slow blow t2 250v fuses blow for no reason?

Hi Colin. Just had a crackle in a left channel (nothing you’ve built by the way), fade to nothing, then that stench of death. Took the lid off my Crimson mono (a simple oblong) and all looks healthy in fact like new, the only thing that’s gone is the fuse. Could it be a mains […]

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COLIN WONFOR: MP/MF330 pre power pair problem

I recently sourced my friend his fab MP/MF330 pre power pair. I was listening to them through his ES14s and could hear a hiss on both channels (slightly more on the right). You need to stick your ear to the speaker, and turning the un-fed pre volume right up didn’t change it too much. This […]

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COLIN WONFOR: Q-20-P preamp and Q-20 power amp test review

Neil McCauley writes: First, here’s how the makers describe their units: Q-20-P The Q-20-P complements the Q-20 power amplifier, it features MC, MM and one line input, a line-level output and a headphone output. The Q20P is designed to be as simple as possible in order to maintain signal integrity. It is ideal for the […]

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COLIN WONFOR: A clean sheet of paper?

Colin – I’m curious about the gestation process you go through designing a new product. How do you normally operate from, say, a clean sheet of paper? Nice question Yes and No is the answer. I love the question. The answer is ‘yes’ for totally new concepts for me.  Getting the prototypes right means confronting […]

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Colin Wonfor’s Clinic: XLR attenuator values

Dear Colin, XLR attenuator values. There is to much gain in my system; DAC outputs 4vrms and amps output full power at 1.6v. What are the correct value attenuators please? Cheers Chris Hi Chris, 1)what impedance are we driving into? 2)what output can the DAC be loaded into? I am going to assume 600 Ohms. […]

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COLIN WONFOR: Howard Popeck speaks at length to people with interesting things to say: Colin Wonfor (Inca Tech, Magnum, Proac-Magnum, T.O.C.A, Naim and Tellurium Q) sets the record straight (Part #1)

The image above is one of just six gold plated issues. Note: This was originally published here in April 2015 Neil McCauley (HFA editor in chief) writes an introduction: Colin was and remains one of the UK audio industry’s gentlemen. No one in our office has heard a negative comment about him nor a negative […]

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Why sell an under-optimized item that can be easily improved upon by the owner or a modder?

Dear Colin, If audiophile grade feet, power cords, and fuses can really improve sound quality, why don’t high end designers/manufacturers just incorporate these audiophile grade components at the time of build? Why sell an under-optimized item that can be easily improved upon by the owner or a modder? I guess you don’t do that at […]

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That elusive valve sound?

Hello Colin, please be patient with me because although I am an experienced listener I’m not very conversant with the technology that is available today. By this I mean I really just plug in and just listen. However recently I started to think about some of the units I use, In particular a Musical Fidelity […]

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COLIN WONFOR: Sources used in product development?

Hello Colin What sources and speakers does you use in development and why please? Thanks. Mike Hi Mike, Now that is a tricky question I like my old Ruark Sabres, they are old friends made for me by my old friend. I also use Spendors, and borrow others makes depending on what I am designing. […]

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COLIN WONFOR: DIY interconnects using Teflon braided hose

Hi Colin. I love your ‘clinic’. Neil promised that you might be offering education for us novices. So may I ask – have you ever thought about using braided hose to run your interconnects. I am talking about type usually found as brake lines on motorbikes and car braking systems, i was messing around with […]

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Colin Wonfor’s Clinic: Step Down Converter – does it degrade the sound?

Dear Colin, I recently saw a 240v integrated amp from the UK and was wondering if it is ok to use with a Step Down Converter? What are the pros and cons of using a step down device? Does it affect the sound and am I in jeopardy of blowing the transformer or ruining the […]

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COLIN WONFOR: Audiophile industry heroes

Hi Colin. Who if any are your audio designers heroes and why? Thanks. Nigel Beethoven (no jokes please) Hello Nigel. Heroes is a bad thing to have as it puts normal humans on a dais and yet they are human. But the gents and ladies in this complex industry that I put up with; the […]

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COLIN WONFOR: 4-Pin DIN plugs to construct an interconnect for a Quad 33/303

Dear Colin, I’ve ordered a pair of 4-Pin DIN plugs to construct an interconnect for a Quad 33/303 system. Do both the channels need to be individually shielded, or is crosstalk not an issue here, and one could use something like this with just an overall shield? http://www.van-damme.com/14.html Failing that, can you recommend a really […]

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COLIN WONFOR: How often do we have to turn off our equipment?

Dear Colin, power supply question. How often do we have to turn off our equipment such as power amp, pre amp. cd player , power conditioner ……? Can we leave them on for days while listening on and off or do we have to turn them off after every session of listening? As a general […]

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