Rega RB300 turntable...
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From: Arfa Daily on 17 May 2010 08:50 "Adam Sampson" <ats(a)offog.org> wrote in message news:y2ahbm66bmr.fsf(a)cartman.at.offog.org... > "N_Cook" <diverse(a)tcp.co.uk> writes: > >> Wasn't Rega tonearms only? > > No, but the RB300 is indeed a tonearm, rather than a turntable. There > are PDF manuals on vinylengine.com for a bunch of Rega tonearms and > turntables which might help identify what the deck actually is. > > It's worth noting that the discussion on the page for the Planar 3 > (which would be a plausible turntable to have an RB300 fitted) has some > comments on replacement motor resistor values, with one comment > suggesting 150 ohm 5%: > http://www.vinylengine.com/library/rega/planar-3.shtml > > -- > Adam Sampson <ats(a)offog.org> <http://offog.org/> Thanks Adam. It is indeed a Planar 3. I had in fact already been on that site, and seen the reference to the 150 ohm resistor. I suppose it's possible that there might be more than one value having been fitted over the life of production, because given 40 odd years of looking at burnt and discoloured resistor stripes, I definitely would not have said that the middle one was originally green, but who knows ? (well, hopefully someone on one of these groups does ! ) I was pretty sure that the first two were brown and red for 1- 2 - something. I was just concerned that if the final band was red, or even orange, I didn't want to be putting 120 ohms in there .... Arfa
From: Arfa Daily on 17 May 2010 08:51 "Meat Plow" <mhywatt(a)yahoo.com> wrote in message news:pan.2010.05.17.12.09.11(a)gmail.com... > On Mon, 17 May 2010 09:57:09 +0100, Arfa Daily wrote: > >> Hi all >> >> Anyone happen to know the value of the resistor in the CR network >> connected in the synchronous motor feed ? Looks like brown - red - brown >> so 120 ohms, but it's well overheated and discoloured, with a nice burn >> mark right around the spiral element, right in the centre. Can't get a >> reading from either end to the burn point. Looks at a guess to be rated >> about 3 -5 watts. Anybody think of a reason *not* to use a wirewound >> rather than the original metal film type ? >> >> Arfa > > Did you try a 120 and see what happens (with some current limiting in > place) With things like this I usually clip in a light fuse in case the > resistor was actually 1200 ohms or more :) If no closer to a definitive answer by tomorrow, Meat, I'll probably go down that route. Arfa
From: DaveD on 17 May 2010 10:11 Arfa Daily wrote: > Hi all > > Anyone happen to know the value of the resistor in the CR network connected > in the synchronous motor feed ? Looks like brown - red - brown so 120 ohms, > but it's well overheated and discoloured, with a nice burn mark right around > the spiral element, right in the centre. Can't get a reading from either end > to the burn point. Looks at a guess to be rated about 3 -5 watts. Anybody > think of a reason *not* to use a wirewound rather than the original metal > film type ? > > Arfa > > Hi Arfa Just took the cover off a Rega Planar 3 and the board has 5 components on it. 1 x .22uf 275v ac cap (220nf) 1 x 10k 5% 1-2 watt parallel (physically) to the cap (bn bk or -gold) 1 x 1M 1% 1/4 watt (br bk bk yell -bn) 1 x 3k3 1% 1/4 watt (or or bk bn -bn) 1 x 120nf 400v dc cap HTH DaveD
From: Arfa Daily on 17 May 2010 12:28 "DaveD" <marday(a)ihug.co.nz> wrote in message news:hsriq2$klj$1(a)lust.ihug.co.nz... > Arfa Daily wrote: >> Hi all >> >> Anyone happen to know the value of the resistor in the CR network >> connected in the synchronous motor feed ? Looks like brown - red - brown >> so 120 ohms, but it's well overheated and discoloured, with a nice burn >> mark right around the spiral element, right in the centre. Can't get a >> reading from either end to the burn point. Looks at a guess to be rated >> about 3 -5 watts. Anybody think of a reason *not* to use a wirewound >> rather than the original metal film type ? >> >> Arfa > Hi Arfa > Just took the cover off a Rega Planar 3 and the board has 5 components on > it. > 1 x .22uf 275v ac cap (220nf) > 1 x 10k 5% 1-2 watt parallel (physically) to the cap (bn bk or -gold) > 1 x 1M 1% 1/4 watt (br bk bk yell -bn) > 1 x 3k3 1% 1/4 watt (or or bk bn -bn) > 1 x 120nf 400v dc cap > HTH > DaveD Hmmm. Well Dave, I've got to say that that bears no relationship to what's in this one, at all :-\ It definitely says "Rega Planar 3" at the top front right corner, although it's hard to see as the letters are just black 'shininess' within the black satin anodised finish of the cabinet. Underneath, directly under the motor, is a cover secured by two screws, When this is removed, the motor and a small PCB are revealed. The PCB has just two components on it - the burnt up R, which is a large 'film' type, I guess something like about 5mm diameter and 20mm or so long, and the 0.22u 400v cap, which is one of those green MKT monobloc types. These two components are mounted 'on the slant' on the board. The mains comes in, and the neutral is joined immediately to two grey wires from the motor. The live leaves the board again on a white wire which goes to the on / off switch at the front top left of the deck. Live returns to the board on another white, and goes to the motor red lead via the burnt up resistor. The cap is between the red lead and the remaining blue lead. Doesn't sound much like the example that you're looking at, eh ? Mind you, dunno about you, but I find this all the time with 'high-end' gear. Guts that are nothing like what the the service manuals say they should be, poorly done mods involving extra components stuck across boards, bog-standard cheap as chips lasers fitted to CD players costing thousands, metalwork that fits where it touches, holes drilled in wrong places, inappropriate screw types and sizes - the list is endless. I know that these things are often hand-built, which I guess is what attracts the people with more money than sense to them, but when I look at some items, I wonder how the companies that made them, and then stuck the multi-thousand pound price tags on them, sleep at night. I guess I've just got too much of a conscience ... Anyways, I think tomorrow that I am going to fit a 5 watt 150 ohm wirewound that I have to hand, and then bring it up gently on the variac, and see what happens. I guess it's got two chances ... :-) Arfa
From: Geo on 17 May 2010 13:32
On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily" <arfa.daily(a)ntlworld.com> wrote: >It definitely says "Rega Planar 3" at the top front right corner, although >it's hard to see as the letters are just black 'shininess' within the black >satin anodised finish of the cabinet. Underneath, directly under the motor, >is a cover secured by two screws, When this is removed, the motor and a >small PCB are revealed. The PCB has just two components on it - the burnt up >R, which is a large 'film' type, I guess something like about 5mm diameter >and 20mm or so long, and the 0.22u 400v cap, which is one of those green MKT >monobloc types. These two components are mounted 'on the slant' on the >board. The mains comes in, and the neutral is joined immediately to two grey >wires from the motor. The live leaves the board again on a white wire which >goes to the on / off switch at the front top left of the deck. Live returns >to the board on another white, and goes to the motor red lead via the burnt >up resistor. The cap is between the red lead and the remaining blue lead. >Doesn't sound much like the example that you're looking at, eh ? How about this version from mine - looks like a 15k 5% (old 2-5w carbon?) http://www.8zero.co.uk/planar.jpg -- Geo |