|
Post by PinkFloyd on Jul 12, 2007 22:38:29 GMT
Got her for £29 and these things retail @ £165 see here not quite sure what I've won here but will deffo give the warts and all here as soon as she arrives. One thing I do know is Canford are the biggest name in the business when it comes to the likes of outside broadcasting / pro audio / BBC etc.... From what I can make out the amp I won (woohoo! a winner!) has XLR balanced inputs, 3.5mm + 6.35mm head outs, can run off a 9V battery or external PSU..... it's obviously a bullet proof piece of pro gear and I have a sneaking suspicion that £29 was one hell of a good buy...... Will upload her guts when she arrives..... XLR to phono adaptors ready to go
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jul 12, 2007 22:54:17 GMT
Nice one, Michael. Look forward to reading your impressions.
|
|
|
Post by PinkFloyd on Jul 12, 2007 23:02:17 GMT
Nice one, Michael. Look forward to reading your impressions. "Michael" is so formal man..... call me "sir" hehe, nah, Mike it is "Mike" I'll be back on this one full spread stylee..... you can count on it Nigela
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jul 12, 2007 23:06:40 GMT
Mike it is.
|
|
|
Post by PinkFloyd on Jul 12, 2007 23:14:24 GMT
Hold on Harry! seems I have won the older Canford amp looks better built do a Google and you'll see the back end of this guy is populated with some nice connectors......Will upload the dirt as soon as she arrives...
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Jul 12, 2007 23:56:15 GMT
Nice one Mike, look forward to reading your opinion on it and hopefully some pictures of the guts
|
|
|
Post by gns on Jul 13, 2007 5:45:14 GMT
Hi Mike, What really pisses me off about this thread is that my old employer, Audionics Limited, Sheffield, England, threatened me with legal action if I ever made it public what I did for them! But sod it! I'm fed up with being Mr Suppressed! I was Senior Engineer at Audionics and they designed and made things for Canford, and the MK1 Canford battery headphone amp came from this brain! There! The buggers will have to do me. If it is the original Mk1, I'll be interested in seeing the pix.
|
|
|
Post by merton on Jul 13, 2007 6:03:54 GMT
how good is it compared to your solo?
|
|
|
Post by gns on Jul 13, 2007 6:57:48 GMT
I'd say it's pretty damn good for what it is. There's no chip-rolling in it, just a 5532 the way it was the day they told me to clear my desk by 6pm back in 93 - "your position has been made redundant Mr Slee"...
I couldn't comment on the Mk2, but would guess Canford themselves added a remote power jack.
I could give you a further history, but the then Managing Director was always quipping the place (parent group, the now defunct Yorkshire Radio Network PLC) was run by the "Sheffield Mafia", and having been threatened once in trying to re-establish myself a few years back, I don't really want to comment much further. By the way, the Managing Director was himself made redundant a month after he gave me the bad news....
But I will add that there's more jealousy, and green feck-eyed envy in the audio industry than is healthy than anywhere in the universe including the surface of the Sun. If you ever lust for evil and crave to know what Hell is like, there's no better place!
The audio industry in general is far more fickle than the music industry, and that's going some.
But back to the Solo: There are quite a few differences - there's a proper output buffer for one, and a lot of attention to power supply decoupling between the op-amp and output stage in the Solo. And if the little Canford features some expensive stuff to quote Mike, then the Solo must be pure platinum!
You see, without being able to give folk my true history, I have a serious problem in getting across to them that I do know what I'm doing.
|
|
|
Post by PinkFloyd on Jul 13, 2007 8:21:58 GMT
how good is it compared to your solo? Haven't got a clue as it hasn't arrived yet! ;D
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 13, 2007 10:42:39 GMT
Out goes the 5532, and in goes
|
|
|
Post by PinkFloyd on Jul 13, 2007 12:25:45 GMT
Out goes the 5532, and in goes Not necessarily, the 5532 may very well be the best chip for the purpose.... it doesn't go by default just because it has "5532" printed on it... in fact, in quite a lot of applications the 5532 is the best chip for the job... it's not trendy though and, as we all know, if it isn't in vogue then it's classed as crap. I'm pretty chuffed to learn that Graham designed this amp... it will deffo be a keeper for that reason alone It hasn't arrived yet, there's a 24 hour postal strike on at the moment (bloody typical) so looks like it will early next week before she arrives
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 13, 2007 12:46:19 GMT
Agreed.The 5532 and 5534 do take a lot of beating in low level applications like microphone amplifiers ans MC phono preamps
|
|
|
Post by PinkFloyd on Jul 14, 2007 17:11:30 GMT
Consider it done. She arrived this afternoon Graham and may I say what a strange looking device it is! I just had to remove that clip that was riveted onto the underside of the chassis, I couldn't get the damned thing to stop revolving about on the deck.... you mean people actually wandered about with this mini brick clipped to their personage? Here's a few of the outside: The clip: XLR inputs (GOOD quality too!) Side view: Is it the rear? is it the top? is it the bottom? I dunno...... Top quality slide out battery holder: Did you notice that uber high quality locking headphone socket? Now let's go inside for a look....... 4 opamps IC1 and IC2 being LF353. IC3 and IC4 being NE5534N. Whilst I was under the hood I thought I may as well socket her "just in case" I get the urge As I said earlier on.... good quality connectors etc. (philips caps too) A very tidy little machine and, you know what? doesn't sound at all bad either..... maybe slightly shrill in places but on the whole quite deep and satisfying... certainly a fair amount of detail getting through. I've already rolled in a few different opamps but she spat them all out for some reason! Seems to only want to play ball with the NE5534 and LF353 on board..... unless I've gone mad NE5534N is a single and LF353 is a dual right?? Swapped out the NE5534 for OPA227, OPA134, AD-843 and zilch.... well there was sound but not as we know it Jim! Swapped out the LF353 for OPA2132, AD-823, OPA2227 etc..... again, there was sound but not as we know it Jim! What the hell..... for £26 (+ £3 shipping) it's an incredible buy and I really do like the mono / stereo switch, flaming great being able to switch into mono It's like an Irish form of crossfeed.... awesome The blurb says I will get 50 hours from one battery.... I'm using rechargeable 9V (6HR61) there is no provision on this version to plug an external PSU in but it will take all of 10 minutes to fit a 2.1mm chassis mount DC socket. Yeh, I like this Graham it makes me feel like some boffin from the BBC... a very industrious hard wearing piece of equipment, hell it would smash your toes if you dropped it If you've got a moment it would be interesting to learn a bit about the design and it would be interesting to know what other chips apart from the NE5532 can be "rolled" in.... I have a suspicion we are looking at the likes of AD797 maybe? Hope these photos bring back "good" memories Graham
|
|
|
Post by PinkFloyd on Jul 14, 2007 17:56:09 GMT
That sure looks good Mike, a pity I do not have any balanced sources to supply that sucker. Maybe I can rig a mini out of the iPod to XLRs using 99.999% cryo silver cables! I am using XLR to phono socket adaptors.... big clumsy looking things, far from "portable" unless you class fitting wheels to this guy and wheeling him about behind you as portable
|
|
|
Post by gns on Jul 14, 2007 19:25:44 GMT
Did I do that?
Huh, 5532 indeed. It was about 16 years ago, and I can remember most of the circuit diagram, but I'd honestly forgot what the layout was inside.
I see it still has the Omeg switched pot, and it has the back-to-back diodes on the balanced inputs just in case it was connected to an LS circuit (LS = loudspeaker). It also has the reverse biased diode across the battery box - protects the circuit but buggers the battery if inserted wrong way round.
I see it still has the old Philip's axial electrolytic's - the Vishay replacements don't look half as good.
The reason it sounds shrill is those little ceramics across the negative feedback resistors. For some daft reason we never used input filters (company policy - not mine), so to stop the op-amps "taking-off" (oscillating), a roll-off above the audio band is used. Please don't take them out. It's not because of the capacitor dielectric, simply that it slugs the op-amps speed. Probably that's why no other chip wants to play?
I think the place only had four op-amps: NE5534, NE5532, LF351 and LF353. The NE's were mainly used for lowest noise or to drive things like headphones (via a resistor...), and line drivers (long cables). Anything else used the LF's, but I'm just starting to recollect that I used the TL071/72/74's in a mixer for the same client - the CCM3.
Canford had tons of those extruded cases, and by the looks of their latest catalogue they still have. So all portable gear had to be made to fit.
The PCB layout was done in Number One's EasyPC standard software on an old 286 Amstrad. The computer stood on an old blue plastic milk crate at the side of my desk (right side to be exact - too much info man...). Those Neutrik sockets were the latest fashion then, and I think we had one "shell release tool" between the lot of us - very frustrating I recall. Notice that rather than saying L and R, it says A and B. Stereo just wasn't "military" enough old bean! You'll also notice that apart from the battery box and mono switch hole, all apertures are Neutrik sized including the plastic blanking disk used for the volume control hole.
What was its purpose though?
It was designed for racks room engineers. Racks in broadcast stations had numerous jack-fields (Mike, feel free to find a picture and place it here), rows of B-gauge balanced wired jack sockets used to route program from one place to another, giving a station the flexibility it needed. A bit like the telephone exchanges you see in the old movies. Being quite complex, you could easily forget what to connect to what, either that, or a fault could occur that needed identifying fast. The headphone amp was clipped to the engineers belt and would have two trailing cables (A and B) plugged into the XLR's, with TRS wired B-gauge plugs on the other end, ready to diagnose the jackfield in question.
As for musicality, the thing the engineer would be listening for was tone - the output of a line-up oscillator from the studio desk in question. But it was designed to do the usual 20Hz to 20kHz to the IBA standards spec (a bit like DIN). I can't remember ever seeing such a spec from the BBC - hush, hush and all that...
Please keep it forever.
|
|
|
Post by PinkFloyd on Jul 14, 2007 22:26:36 GMT
You must have Graham, it sounds bloomin' good 10K log and the switching module strapped on the back is a Lorlin MS2000 module, it's actually a pretty damned accurate pot mate. Pretty much bullet proof, the only minor niggle is the 50mV of DC offset on each channel (+47.4 mV and +48.2mV respectively) pretty much negligible but it's always nice to have closer to 0mV. Good quality battery box too, a spring loaded Bulgin... it employs far from cheap parts, especially the connectors, it's obviously been designed to last a lifetime and withstand the rigours of daily use and abuse in the pro environment.... pretty much bullet proof all round. Sonically it's a little gem, it manages to convey a helluva lot of detail and the background is inky black silent.... my first dedicated battery powered amp, I'm loving it already! The first thing my eyes homed in on when I opened her up.... they're not going anywhere fantastic sounding caps they just don't make them like that these days.... pure quality As it happens the "shrillness" has now totally gone, I don't think this particular amp saw a lot of use and now she's been on for 6 hours things have really opened up and "blossomed" No way am I going to take anything out or put anything in Graham.... I like the sound as it is.... pretty damned certain that's why the other opamps don't want to sing, well they can bugger off and sing in another amp.... I'm keeping this baby as stock, there is nothing that offends and quite a lot that pleases so it will remain "as is". I just had to remove that belt clip thing though and fit some rubber feet, it can always be retro fitted should the need arise but this time with nuts and bolts and not with rivets Good staple opamps and opamps which appear in 90% of the equipment that makes / records music.... People talk about "synergy" yet the first thing they want to do is "get rid of that horrible NE5532 / 34" Think about it, if they wanted perfect synergy they'd use the same components through the chain, from mixing desk to home reproduction gear... if the music has been recorded through equipment utilising NE5532 then why throw a spanner into the works further down the chain and bung in an OPA627? It will sound different, yes, but not necessarily how it sounded to the recording engineer.... anyways, I'm waffling...... And nice cases they are too, these things have been built from the ground up and are not a "remove 8 screws and roll in an opamp of your choice in one easy step" type of thing.... they're very well put together using very good quality, long lasting parts. Yup, quality on a stick! I note the MKll they are now selling utilises an el cheapo head socket and also boasts "new circuitry" I bet you a pork pie the MKll doesn't come anywhere close to your original in either sound quality or quality of construction. They quite simply couldn't afford to punt out the quality of the original for £164 (or whatever it retails at now) I can bet my bottom dollar the MKll has been really paired down to the bone, I'd be interested in finding out.... this little amp has taken me by surprise, I seriously didn't expect it to pack such a punch both sonically and build wise.... for no other reason than curiosity it's worth having a listen to the MKll. Canford say about the MKll and I quote: " A new variant on an old theme, we introduce our Battery Powered Headphone Amplifier Mk2. The original version was introduced ten years ago, so it was time for an update. The new version has entirely new circuitry, whilst retaining the same appearance in our familiar extruded case. This stereo amplifier runs off a PP3 battery for up to 50 hours or an external DC supply, and connects stereo headphones to nominally line level sources. Two inputs are provided using XLR's, and the headphones can plug into either 6.35mm A-gauge and 3.5mm stereo jacks. A three-position slide-switch selects between A/B stereo or MS formats on the XLR inputs, or mono (A+B). We have an adapter cable as well, with a 3.5mm stereo jack plug, to connect the amplifier to PC sound cards, Walkmans and other miniature equipment." " The original version was introduced ten years ago, so it was time for an update" Statements like that piss me off big time! Time for an update because it was becomming too expensive to produce or time for an update just for the hell of it? Why "update" something that does the job and does it bloody well. The classic 80's / 90's con of "MKll tuned for the British market" (ie:quality Jap gear stripped of expensive parts and marketed as tuned for our ears.... bollocks.... "tuned" to save money on parts") The shpiel about the changes to the MKll go as follows: Canford Audio have launched an updated version of their popular Headphone Amplifier, which allows the user to monitor MID & SIDE signals in addition to mono and stereo signals.
The unit, used in conjunction with a pair of headphones, allows audio signals to be checked quickly and easily in many situations, but is particularly useful in the broadcast environment.
A three-position slide switch enables the user to choose between Mono, AB and MS, expanding the list of situations this already versatile unit can be used in.
The inputs are by two high impedance XLR sockets on the top of the device, both electronically balanced and both with DC protection. The headphone outlet is via either a 6.35mm A-gauge jack or a 3.5mm jack and the maximum output has been increased from +8 to +13 dBu. There is a dual gang volume control located on the top panel while on the rear of the unit, adjacent to the DC input jack, a three-position toggle switch selects between internal battery power, external power and off.
The unit is housed in extruded aluminium and a beltclip is provided.
Combined with the battery compartment's location beside the headphone socket, this is a very compact and extremely portable little gadget.Granted, it sounds a lot more user friendly. It now has a toggle switch to select between internal battery power, external power and off where the original only had on / off via the volco and was battery only. The maximum output has been increased from +8 to +13 dBu, you can now use 'phones with a 3.5mm or 6.3m jack and you can now monitor MID & SIDE signals in addition to mono and stereo signals. Certainly a lot more adaptable sounding and, who knows, it may make music just as sweet (or even sweeter) than the original.... I'm a pessimistic bastard and always expect quality to go downhill as time passes by, I'm probably VERY wrong thinking that way and there's every possibility the MKll will actually sound better than the original...... I didn't even know Canford sold headphone amps a week ago and now I learn not only do they sell headphone amps but Graham designed the original! This is a fascinating hobby isn't it? the road to audio Nirvana is full of surprises I'm liking this more and more... an actual "tool" used by audio engineers and not a wankfest sitting on someone's "desktop" full of boutique parts..... I think I can now understand why the Solo sounds so damned good man, you've designed it to convey every last ounce of the signal to the ears and have refused to compromise and give in to those who demand pretty looking circuits populated with overrated expensive parts.... you're still at ground level in the recording studio and letting the music pass through "as is" you haven't yet sold out and gone to the third floor and poured a gallon of syrup into the equation..... keep doing what you're doing mate, keep it simple keep it real.... eventually everyone will see (or should I say "hear") that your grounding, experience, passion, love for music and implementation (gained through years of in the field experience) all make perfect sense. It's taken me a while and a lot of expensive detours with exotic caps, opamps etc. but I am now firmly in your camp, you have an uncanny knack of making music sound like music..... long may it continue. I just can't believe I'm listening to such "real" music and the damned thing is not even plugged into the mains..... 7 hours now on a LIDL rechargeable battery and nothing but toe tapping, enjoyable music..... No way will I be getting rid of this puppy, not now not ever, if this was one of your early jobs then I seriously have my tongue hanging out in anticipation of the Voyager. Mike.
|
|
|
Post by PinkFloyd on Jul 15, 2007 13:35:42 GMT
Similar to this Graham? Or more like this
|
|
|
Post by PinkFloyd on Jul 15, 2007 21:41:13 GMT
Just out of interest Graham I may pop the ceramics out and try a few different opamps.... the amp is now socketed it would be a shame not to.
|
|
|
Post by gns on Jul 16, 2007 0:11:10 GMT
Hi Mike,
They are there to prevent instability and with no input filters, be careful.
You could try putting a 100pf good quality cap like the ECQB range from Panasonic from each op-amp input pin to ground (I mean the actual input, not the feedback input) to protect against instability passively. I forgot the value of the balanced section input resistors, but if these are larger than say 15k, then a smaller value ceramic would be better there, or you'll lose the top end phase "integrity".
Or...
Another way would be to put the 100pF's across the op-amp's "+ and -" input pins (strapped across pins 2 and 3, and pins 5 and 6 too for the duals), in fact, that could be the better idea, and you'd not need the smaller values as they act as a bootstrap.
If you get any instability it should exhibit itself as radio pick-up.
Have fun.
|
|
bullpup
Been here a while!
How much is that doggy in the window?
Posts: 517
|
Post by bullpup on Jul 31, 2007 21:05:02 GMT
Any update on this Mike or are you just sitting back and enjoying the sounds?
|
|
|
Post by colonelmustard on Feb 27, 2013 21:39:57 GMT
I know this is and old thread, but made interesting reading. I get asked on shoots often by cameramen why the headphone output won't power a line input, and it sounds really quiet. And I often enjoy the confused look on their faces when they hear the black buzz magic words like level mismatch and impedence. i throw in a typical car comparison with a cinquicento pushing a volvo or something and go back to my work grinning. anyway enough of my sound mixer bitterness.
I'm actually also curious about the canford headphone amp because someone ("gns") mentionned he worked on the circuitry and also on a mixer Canford Audio CCM3. I'm trying to find out about this mixer and I find absolutely nothing. The thread is old now so maybe the people are no longer connected. But if you are please could you drop me a line.
the whole story about the sheffield mafia too? As a Sheffield lad myself, Made for very nostalgic reading.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 27, 2013 21:48:44 GMT
Graham Slee is ex BBC, and you can contact him through his website. Regards Alex www.gspaudio.co.uk/
|
|