Unused kit lying around; does it deteriorate?
- Thread starter Mike Reed
- Start date
the caretaker
pfm Member
I have noticed on a couple of pairs of my speakers the vinyl wrap is starting to come off! Grrr these are my old cheap speakers tannoy f1 really bad..almost come off completely..stil sound ok..and a pair of my dynaudios look a bit suspect too.
Arkless Electronics
Trade: Amp design and repairs.
Clearly says that it's bad practice to power up any (ANY) power amp without a speaker or resistor connected. Presumably that goes for s/s too! Maybe it's simply the circuitry/design of the Leak which proscribes this practice, but I'd've thought this unlikely. Maybe the Leak has minimal or no feedback?
Why is nothing simple in hifi (or life?).
NO!!! SS amps do not mind having no load in the slightest bit.
In spite of what it may say in the instruction manual it is perfectly safe to power up a stereo 20 without a load and the same applies to most similar valve hi fi amplifiers. I don't tend to do it myself as it is "bad practice" with a valve amp but to just switch it on with no music playing will be fine.
I inherited a turntable from my father that had been used for no more than a few hours before my mother told him to remove it from the lounge since he already had radio, cassette and CD players and didn't need it. The latter were out of sight in a cupboard with sliding doors but the turntable was unfortunately on top in full view. It went into the loft for 20 or so years and was beyond salvaging due to corrosion when I got it.
Arkless Electronics
Trade: Amp design and repairs.
NO!! Valve and transistor amps are exact opposites on this. Shorting the output of a transistor amp will kill it. Even if you just lightly and swiftly touch the speaker leads together...unless there is protection circuitry to save it and even then it may not deal with this. You can use it as much as you like at any volume with no load...
Valve amps will handle short circuits no problem at all but, as I said up thread, it is bad practice to operate them without a load. It is only a real mega no no though with certain types of valve amps and the technical reasons are beyond the scope of this discussion.
This is my nightmare with unused speakers especially if they are being tucked somewhere out of sight, and when you go and check it the physical appearance has turned quite undesirable. This will not only happen to cheap old speakers but considerably new modern speakers as well. In my case, I noticed some white-coloured stuff forming on the fabric of my speaker grilles. I quickly used a slightly damp cloth to remove the spots and fortunately they are not permanent marks.
Also, if there are screws around the woofer, check for oxidation marks or dirt but these can be cleaned off easily with Deoxit.
Tony L
Administrator
In fairness solid state amps didn’t even exist back then!
PS I’d not power up any valve amp without a load (resistor or speaker). Most state this clearly in the user manual, as does the Leak. No issue at all with solid state. Not even Naim!
Mike Reed
pfm Member
I had my first s/s amp (Truvox followed by Leak Stereo 30) in 1964/5). Although Leaks etc. had been going for ages beforehand, I thought they were still being produced in the mid sixties. A number of others certainly were (Radford, Quad, e.g.)
Ho ho ! (even Naim). I used to have three sets of speakers in different rooms fed from my (then) 250 and used to simply unplug and plug in as required, taking great care, of course. This was a very big Victorian house and I ran the cables under the floor and through the cellars. I used to do a lot of cooking and the meals were more delicious when prepared with music but the kit was a long way from the kitchen.
Tony L
Administrator
I was assuming the manual dated from the Stereo 20’s introduction in 1958 (it was as far as I’m aware the UK’s first stereo amp and introduced the same year as the stereo LP). I have two Stereo 20s, a bronze one from 1961 and a grey one from ‘65. I think their manuals are the same, though I’d need to check. The Stereo 20 manual schematic is actually well known for not necessarily representing what is in the amp, my bronze one certainly indicates earlier circuit values than were in the amp when I got it!
I should have been clearer there! I wasn’t having a dig, just pointing out it is perfectly safe to leave a Naim power amp on without anything connected to it even though there is a usage requirement for a specific type and length of speaker cable in actual use. Basically as there is no circuit with the speakers disconnected it can’t react/oscillate, so is perfectly safe (to the best of my understanding).
Barrymagrec
pfm Member
As a general rule SS amplifiers will be fine without a load, valve amplifiers however sometimes not. The reason is the that without a damping load on the output transformer some amplifiers will oscillate at high frequency and this can produce extremely high voltages on the primary of the transformer causing insulation breakdown and a consequent large repair bill.
Some valve amplifiers, notably Quad used to state that they were unconditionally stable into any load but it`s unwise to rely on this if you are not absolutely sure of the amplifier spec or service history.
Some valve amplifiers, notably Quad used to state that they were unconditionally stable into any load but it`s unwise to rely on this if you are not absolutely sure of the amplifier spec or service history.
Tony L
Administrator
I thought that ‘unconditionally stable’ thing came in with the 303, which is pretty much bomb proof e.g. it won’t blow up if shorted (Walker used to dem it by sticking a screwdriver across the terminals, music would stop, then come back when short removed). It doesn’t sound at all good into low impedances though. I’ve never heard the II mentioned in that context, though obviously a short doesn’t worry a valve amp as much as open circuit.
Just some gidance, as most people do not seem to appreciate these facts -
No simple polymer, typically polyethylene, bag is moisture-proof - they breath water vapour pretty fast. What they will help to reduce or eliminate is condensation on anything that is stored where temeparture and humiduty swings can be large and swift (lofts). The thicker the polymer film, the better.
Metalised polymer film is a FAR better moisture (and gas) barrier that untreated polymer - hence those laiminated bags/pouches for long term food storage and metallised film crisp bags and the like.
Aluminium foil is even beter if you can make a decent rolled or folded seal all round.
Rubber components in storage are mostly attacked by the minute traces of ozone that exist at ground-level. Only foil is a reasonably effective barrier against that.
Always assume that any item that is stored anywhere but in a warm, ventilated room, is damp - ideally leave somewhere warm for at least several hours before firing-up, even against a warm radiator is absolutely fine.
No simple polymer, typically polyethylene, bag is moisture-proof - they breath water vapour pretty fast. What they will help to reduce or eliminate is condensation on anything that is stored where temeparture and humiduty swings can be large and swift (lofts). The thicker the polymer film, the better.
Metalised polymer film is a FAR better moisture (and gas) barrier that untreated polymer - hence those laiminated bags/pouches for long term food storage and metallised film crisp bags and the like.
Aluminium foil is even beter if you can make a decent rolled or folded seal all round.
Rubber components in storage are mostly attacked by the minute traces of ozone that exist at ground-level. Only foil is a reasonably effective barrier against that.
Always assume that any item that is stored anywhere but in a warm, ventilated room, is damp - ideally leave somewhere warm for at least several hours before firing-up, even against a warm radiator is absolutely fine.
Sony minidisc decks use a tiny & I mean tiny belt as part of the eject mechanism that will stretch whether used or not over over time in situ so that the disc wont eject. Best to remove it. I dont use my Xerxes record player much these days so remove the belt.
Regarding speakers what about those that use tweeters with that black heat dissipating ferro fluid goo? How long before that dries out and tweeters stop performing as they should due to partial seizing up? I did get some some time go but so far havent had the courage to do anything . Has any one experienced this happening and replaced the goo and with what results?
Regarding speakers what about those that use tweeters with that black heat dissipating ferro fluid goo? How long before that dries out and tweeters stop performing as they should due to partial seizing up? I did get some some time go but so far havent had the courage to do anything . Has any one experienced this happening and replaced the goo and with what results?
Barrymagrec
pfm Member
Quad certainly used the unconditionally stable" tag for the II, I remember a technical advice article in an early sixties HiFi News where someone was wanting to feed another amplifier from the output of a Quad II, the advice was that it would be O.K. because the Quad was very high quality but that they should put a 15 ohm resistor across the output as there was no speaker. The next month the letters page had an irate letter from Quad saying this resistor was not required - "unconditionally stable is no idle boast".
The stability of the Quad II was used as a reason not to drive the ESL with anything else, it being a difficult load by the standards of the time - the fake ESL load used in HiFi News amplifier tests at that time showed up some pretty iffy square waves from some amplifiers under test.
Was that the CT-S830S? If so that was me. The fix was a pair of voltage regulators in the power supply, 2 shorted caps and all of the belts. Not the easiest deck to work on but well worth the effort. All working well now though and still very much appreciated.
miktec
retired
I had a couple of items that spent a long time unused (a Braun TT for about 6 years in dry storage - a modular ILP power amp for about 8 in a damp garage)
Both started up fine and neither showed any signs of losing performance abilities. Same goes for a pair of B&W 10 that lived permanently in the garage - although one of the cabinets did suffer water damage.
Only real victim I've had was a Mac Mini I used to use in the garage - unused during the Winter months. Come one Spring I powered it up and wifi refused to work.
When I took it to bits it transpired some insect (prob a spider) had laid its brood on the wifi card - and the goo had clearly rotted the circuit. A new card and all was well.
Reminiscent of Aranofsky's film "Pi"
Both started up fine and neither showed any signs of losing performance abilities. Same goes for a pair of B&W 10 that lived permanently in the garage - although one of the cabinets did suffer water damage.
Only real victim I've had was a Mac Mini I used to use in the garage - unused during the Winter months. Come one Spring I powered it up and wifi refused to work.
When I took it to bits it transpired some insect (prob a spider) had laid its brood on the wifi card - and the goo had clearly rotted the circuit
. A new card and all was well.Reminiscent of Aranofsky's film "Pi"
wylton
Naim and Mana member
Arkless Electronics
Trade: Amp design and repairs.
Strictly speaking.... unconditionally stable does not mean what it says. It comes from control theory as does so much of feedback theory and goes back to long before SS amps!
I use it in the same way as Quad and any sensible person though
The Pye push pull amps manual also says it's OK to use them without a load FWIW as you have to when setting up the adjustable damping factor to your speakers.