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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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22nd Feb 2021, 4:26 pm | #21 |
Dekatron
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Re: Sugden preamp WAL AC Farnell.
The manufacturing rights to WAL products were sold to A.C. Farnell circa 1963 by the founders widow, the founder was Roy N. Wellington.
Lawrence. |
22nd Feb 2021, 8:50 pm | #22 |
Triode
Join Date: Feb 2021
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Re: Sugden preamp WAL AC Farnell.
Thanks everyone, such a torrent of illumination.
Initial response on the unit from the manufacturer: - The unit hasn't been seen before. - The circuit boards are not from another Sugden product. - It was built for a special purpose, possibly part of a test rig. - The circuit boards are estimated at 1967-8. Curiouser and curiouser. |
22nd Feb 2021, 8:59 pm | #23 |
Triode
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Re: Sugden preamp WAL AC Farnell.
So AC Farnell may well have commissioned J.E. Sugden to produce this WAL unit.
But to what purpose? As a prototype for further manufacturing? And how good is the sound quality likely to be? Some of the comments on the excellence of some of the components suggest that it might be surprisingly good. |
23rd Feb 2021, 12:52 am | #24 |
Octode
Join Date: Mar 2016
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Re: Sugden preamp WAL AC Farnell.
I'm glad to know that Sugden replied to you. They make good stuff (I scrutinised one of their current offerings with my R+S analyser), and it's nice to know that they took time to reply to you. I have pieces from several OEMs that are off-radar and either they don't reply, or when they do, they simply tell you it's discontinued and suggest that you ought to take a look at their latest offering.
I think you have several options: i) Plug it in and have a listen. I'd suggest powering it with a variac before doing this, as the caps may not have been powered for decades. Although it's most likely cap-coupled everywhere and is unlikely to harm anything connected to it, if you want to be careful, run around all inputs and outs with a DVM and check that nothing resembling DC is coming out. If you like the sound, does it matter what anyone here says? My feeling is that it'll likely sound ok, assuming you connect it to the right type of cartridge. As Craig suggested, the old filter caps could mean hum performance isn't great. ii) Are you looking to learn about audio electronics? If so, get yourself a generator (soundcard + freeware will also do it) and a scope. You can then test it for yourself and do some basic measurements. It'll take a little time, but you'll learn plenty. iii) Find someone with an audio analyser. This will tell you exactly what its functions are in about 2 minutes: whether the output is flat, noise level, gain etc. But where would the fun be in that? And it'll bias your attitude towards listening to it. Audio electronics have been good for quite a few years now.. They had discrete transistors in the late 60s that could be used to make signal paths that are quiet enough to be used with modern digital gear. The late, great Rupert Neve used the BC184C and BC109 in his designs, and these preamps are more desirable today than ever. |
23rd Feb 2021, 5:50 am | #25 |
Nonode
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Re: Sugden preamp WAL AC Farnell.
WAL preamplifiers were listed in Hi Fi Year Book 1967-68, then under Elstone Electronics.
These were battery-operated units for matching tape, microphone, or pickup inputs. That suggests that they were intended for use with amplifiers or control units that did not have low-level inputs, not too uncommon at the time. And there were other makers of this kind of preamplifier for domestic use. Evidently WAL moved on to mains powered units of the same basic type. I imagine that the three-way selector was less intended for daily use than to preset the unit for specific applications. Magnetic cartridge matching and equalization may have bene the main objective, but as the same basic circuit could easily be configured for use as microphone or tape head preamplifier, it would have been easy enough to include those facilities. Re Sugden’s involvement, the disc preamplifier section of its C51 control unit, although mostly intended to do the RIAA job, was configurable for microphone, and tape head inputs, as well as for different disc equalization curves. I think that there was also a plug-in for the A.R. Sugden ceramic cartridge, which was something of a maverick amongst higher quality ceramics in terms of its characteristics and required loading (it was outside of the range of the Burrows parameters.) So perhaps the design of the subject WAL unit drew from that of the Sugden C51. Cheers, |
23rd Feb 2021, 9:49 am | #26 |
Heptode
Join Date: Jan 2006
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Re: Sugden preamp WAL AC Farnell.
It seems that WAL was transferred to Elstone Electronics by 1963 (the Studio Sound advert) and Elstone Electronics had been taken over by AC Farnell by 1966 at the latest. Presumably Farnell gave up manufacturing electronic devices and got J.E. Sugden to produce a new version of the WAL Gain but the crucial questinm is when? The J.E. Sugden C51 preamp didn't come out until 1969. A.R. Sugden (manufacturer of the Connoisseur turntable) was a complelely different company.
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23rd Feb 2021, 12:47 pm | #27 |
Octode
Join Date: Mar 2016
Location: London, UK.
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Re: Sugden preamp WAL AC Farnell.
Has it got a ground post for the TT chassis / arm? Did TTs from this era common chassis GND to the cartridge -v side?
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23rd Feb 2021, 1:22 pm | #28 |
Triode
Join Date: Feb 2021
Location: London, UK.
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Re: Sugden preamp WAL AC Farnell.
Thanks everyone for the new contributions, really excellent.
Can confirm that it doesn't have a ground post for the TT chassis /arm. Looked at some Sugden C51 pictures and can see some overlap of components on the boards, others may be able to discern more. |
23rd Feb 2021, 8:22 pm | #29 | |
Nonode
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Re: Sugden preamp WAL AC Farnell.
Quote:
Although the C51 had a prior life as the C41, under the Richard Allan name, this having been announced in 1968 April, along with the A21 integrated amplifier and A41 power amplifier. Sugden seemed to have been particularly interested the matching and equalizing of pickup cartridges at an individual model level, as evidenced by his fairly well-known article in Hi Fi News for 1968 April, “Flatten Your Head”. The individual cartridges mentioned therein also appear in the C51 data as being catered for by special input circuit arrangements. I suspect that it was the same for the C41. Inclusion of the A.R. Sugden Connoisseur cartridge in that list may have been an artefact of the “Yorkshire Triangle”. Anyway, one could say that c.1968, Sugden was well-positioned to design and supply a third-party disc/mic/tape preamplifier, and that one might expect such to include some of its own thinking as to how this task should be addressed. In the absence of other evidence, the circumstantial case points to 1968 as the introduction date for the Sugden-built WAL preamplifier, but it might have preceded the C41, so 1967 is not outruled. Cheers, |
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23rd Feb 2021, 8:48 pm | #30 |
Moderator
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Re: Sugden preamp WAL AC Farnell.
It's at the point where I think the circuit needs tracing out. Then it can be compared to various published designs and that Hifi News article. I wonder if 'Tape" means tape head?
Without any controls, I think this is really a pre-pre-amplifier to add high sensitivity for low output sources like dynamic mikes, magnetic cartridges and tape heads.... things not normally included in most preamps. David
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23rd Feb 2021, 11:18 pm | #31 |
Octode
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Re: Sugden preamp WAL AC Farnell.
It could have been designed for a Bingo Hall ;-)
I once had a mixer from the early 70s from one. It was in beautiful nick, as the only pot that had seen any use was the mic -) |
24th Feb 2021, 7:49 pm | #32 |
Heptode
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Re: Sugden preamp WAL AC Farnell.
The original WAL Gain was certainly meant to be used in a hi-fi system rather than a bingo hall as this advert from The Gramophone in 1958 proves.
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24th Feb 2021, 9:38 pm | #33 |
Triode
Join Date: Feb 2021
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Re: Sugden preamp WAL AC Farnell.
Thanks again for these contributions.
So we can say that ten years after this advert from 1958 a version of the WAL Gain pre-amplifier was still considered to produce sound quality sufficient to merit its selection for incorporation into a test rig unit built by J.E. Sugden and commissioned by A.C. Farnell. Fair to say that there was probably excellent oversight available in both companies. Is it possible that this particular unit’s WAL Gain design was seen as something special? Would key personnel in either of these eminent companies have been content with putting effort and expense into designing and building a new device that was likely to provide, by 1968, second rate output or be judged as technologically somewhat behind the curve? |
25th Feb 2021, 1:15 am | #34 |
Dekatron
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Re: Sugden preamp WAL AC Farnell.
If the 1958 version used silicon transistors, it must have been really early - the first silicon transistors only became available three or four years earlier.
I suspect it might have gone through at least one design revision. |
25th Feb 2021, 10:01 pm | #35 |
Heptode
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Re: Sugden preamp WAL AC Farnell.
Why do you think the 1958 version might have used silicon transistors?
The first version was mono ; a stereo version came out a few months later. I have discovered that Elstone Electronics was incorporated into Farnell in 1945(!) so the transfer to Elstone was also a transfer to Farnell as an earlier post stated. |
26th Feb 2021, 12:23 pm | #36 |
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Re: Sugden preamp WAL AC Farnell.
This is a typical WAL device a little in line battery powered amplifier.
Unfortunately the label has peeled a little but it used to say Elstone. Date late 50's early 60's at a guess. The case size was determined by the battery (PP7). The Sugden unit is way more sophisticated and higher quality. Cheers Mike T
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26th Feb 2021, 6:46 pm | #37 |
Heptode
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Re: Sugden preamp WAL AC Farnell.
I think that's an original 1958 mono WAL Gain which has been "badge" engineered by Elstone.
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26th Feb 2021, 8:13 pm | #38 |
Heptode
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Re: Sugden preamp WAL AC Farnell.
Germanium transistor apparently
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26th Feb 2021, 8:58 pm | #39 |
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Re: Sugden preamp WAL AC Farnell.
It's an STC TK45C also marked ACY29
According to Mr Transistor this happened around 1962/63 http://www.wylie.org.uk/technology/semics/STC/STC.htm So its a little later than I first thought. Cheers Mike T
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27th Feb 2021, 12:55 am | #40 |
Heptode
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Re: Sugden preamp WAL AC Farnell.
Your pictures show a remarkable resemblance to the original mono WAL Gain pictured in the Gramophone in June 1958. Perhaps Elstone bought all the remaining cases as well as the manufacturing rights.
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