Rega RB250 advice please

[Spur07]

Hi all,

bought a used Nad 533 the other day and decided to check the arm so downloaded instructions from Rega website. I'm afraid I'm not greatly knowledgeable with vinyl - can someone explain the bit in yellow :scratch: I guess there's a typing error and it's thrown me.

With the cartridge fitted and aligned using the
alignment protractor supplied, ensure that the bias
adjustment slider is set to zero. Screw the balance
weight along its shaft until the stylus is “floating” just
1mm clear of the record.
The recommended tracking force can now be applied
by rotating the balance weight so that it moves
towards the front of the arm. A half turn gives 1g
tracking force. The black plastic plugs on the weight
can be use a force which corresponds to the upper
limit of the cartridge makers recommended range.
Set the bias adjustment slider to the same number as
the tracking force control -
i.e. 1 1/2 g tracking force = 1 1/2 on the bias slider.

Paul

[freefallrob]

On the counter weight there is a black plastic plug (underneath is the ball and spring which locates on the grooved arm stub).
In the description they are referring to this as a visual marker when the arm is balanced, you then turn the counter weight towards the pivot to provide the tracking force, ie 1/2 a turn to 1 gram tracking force (using the plug as a visual reference), set to what your cartridge requires, go for the maximum recommended.

The above will get you in the ball park, but really you could do with a simple stylus force gauge it would make it easier and more accurate.

Something like this http://www.audioaffair.co.uk/Clearaudio-Stylus-Force-Gauge/product_999

or similar there loads about.

Set the bias to roughly 3/4 of the tracking force, on a RB250 usually set it about half way...

You cold use a test record to set these things up, or just what sounds best to you.

[DSJR]

As above. One thing to check while you're at it. SOME of these arms had rattly bearings, although Rega sorted it later on. if there's ANY rattle at all (hold headshell and gently try to "rock" it), get the arm serviced, since it can make a world of difference. The better the deck and cartridge, the bigger the difference I found...

If the bearings are ok, and the nuts holding the arm and main bearing to the plinth are firmly but not excessively tight, I really would ditch that horror of a Goldring cartridge many of these decks came with. You can do so much better and even an AT95E will do fine :)

[Spur07]

Thanks Rob and Dave, I'll give it a test out after I've had some diner :) Actually, I've got quite a few questions to ask as I'm planning to maybe get a Lenco L75 and build a plinth eventually transfering the RB250

Dave, what was the Goldring cartridge that came with the 533, it's bright red?

[DSJR]

An Elektra IIRC... Dull in the extreme and didn't track hugely well either I remember.

PLEASE don't buy a GL75 with the intention of butchering it!!!!! It upsets me so much when a perfectly adequate arm is shamelessly removed to be replaced with a REGA arm, of all things. Getting a GL75, putting it in a decent plinth (Russ Collinson makes some good ones) and getting the arm re-"blocked" (Desmo blocks) and with new exit wires (Van Damme pro-Patch) will enable a level of performance the original couldn't quite achieve IMO and the addition of any good 1.5 - 1.75g tracking cartridge (Shure M97XE, Ortofon 2M, DL110 and so on) will lift the sonics to new heights I reckon. Obviously just my opinion..

[Spur07]

I've set the bias adjustment to zero and just trying to float the arm 1mm from the record by moving the weight but the arm wont stand still without me holding it. It keeps wanting to go back to its resting position and the further it does the higher it goes, and the nearer it gets to the record the lower it goes. This all seems a bit daft.

Is it okay to use my finger to gently stop it from returning to its holding position?

[hifi_dave]

Make sure the TT is on a flat, level surface.

The arm will always swing when the tracking force is set to zero, as the bias is always active. Bias is via two magnets and can never be switched off entirely.

It's OK to steady the arm with your finger, to allow you to carry out adjustments etc.

[Spur07]

oh dear, got a feeling I've done something wrong here. don't know if its my ears but the music sounds slow, cumbersome and the bass bloated. doesn't help that my amp needs a good service - the phono stage keeps dropping one channel or the other.

Knew I shouldn't have touched it :( but the bias slider was previously set to zero.

[keiths]

... PLEASE don't buy a GL75 with the intention of butchering it!!!!! It upsets me so much when a perfectly adequate arm is shamelessly removed to be replaced with a REGA arm, of all things.

:sofa:

Oops.You're not going to be very happy with me Dave. :o :donk:

I've had a GL75 for a few weeks now. I tried with the L75 arm, I really did. Replaced the V-blocks with Desmos, shored-up the wonky counterweight stub with dental floss and superglue, replaced the output cabling with Van Damme 'Tour Grade' mike cable and Neutrik phonos and fitted a Shure M75-EJ2.

But I just couldn't get on with the arm. It still felt clunky, about to fall to bits at any minute and something from another era (which of course it is :doh:). I'd never have been happy with it.

So my GL75 is now about to be butchered within an inch of it's life - DIY multi-layer birch-ply plinth, 'PTP4' top plate, Rega RB300 (and later, electronic speed change).

Sorry :(

:ner::ner::ner:

[keiths]

oh dear, got a feeling I've done something wrong here. don't know if its my ears but the music sounds slow, cumbersome and the bass bloated. .

Are you sure the VTF (tracking weight) isn't set too high?

[Spur07]

Are you sure the VTF (tracking weight) isn't set too high?

I guess so Keith. I'm going to give in and buy a stylus force gauge as per Rob's suggestion as I think maybe I'm pissing in the wind a bit with that. The recommended tracking force of my cartridge is 1.5 - 2g, so using the black plastic stub as a guide I rotated the weight 1 further revolution toward the front of the arm. I set the bias slider to 1.

I'm very interested in your multi layered / PTP plinth for the Lenco. Did you get the plans from the Lenco Heaven forums? How much did you pay for your Lenco?

P

[DSJR]

Set bias to zero. Adjust counterweight so the stylus "floats" just above the surface of a record (the magnetic bias correction never fully disengages, so the arm will always return to the rest position - hold the bearing cradle in place to confirm proper balance).

Return the arm to it's rest, clamp up and then carefully screw the counterweight in towards the pivots by 7/8 of a turn. This will give you 1.75g tracking weight to pretty good accuracy. Set the bias slider to NO MORE than "1" and that should be it.............

[keiths]

I'm very interested in your multi layered / PTP plinth for the Lenco. Did you get the plans from the Lenco Heaven forums? How much did you pay for your Lenco?

P

Hi Paul,

Yes, all the info has come from Lenco Heaven. My plinth is going to be 10 - 12 layers of 18mm birch ply each 480mm by 380mm. I'm going to use a new top plate ('PTP4') bought from Peter Reinders who advertises them in the trade section of LH. This top plate is almost entirely hidden by the platter which gives a very clean and minimalistic appearance. Eventually I'll add electronic motor control/speed change - Sander's/Nigel's Motor Controller - there's a thread following the controller's development on LH where you can sign-up for the PCB and the schematic etc.

The GL75 cost £46 off ebay and is in very good condition except for the old plinth, which is tatty and the dustcover which is badly cracked. It's also missing it's antiskate weight (easily improvised) - but I'm replacing the arm anyway.

I've stripped and serviced the bearing and the motor using "Joel's Kit For A Better Lenco" (off ebay) - replacing both the ball bearing and both bearing and motor thrust pads - following the instructions from the "How To" section of LH.

So there's a big pile of plywood and a very scary-looking router sat in my kitchen waiting for me to get started. :scratch:

[DSJR]

Like I said, why are you "replacing the arm anyway????" Why just assume an RB250 is going to sound far better 'cos it's modern???

Marco here has already shown just what can be done with a detachable shell tonearm such as the Jelco, which can't be much less massy than the Lenco one. PLEASE don't just assume that following the sheep in this instance (I'm going to buy an RB250 'cos everyone else does - baaaaa) is going to bring about the transformation you seek, when you have an actually pretty good tonearm there already, just waiting to be fettled and used sympathetically with the cartridges I've already suggested... :ner:


Someday, someone like Arthur is going to get hold of an L75 bearing block, which features good ballraces, fit and finish and fit an up-to-date arm tube, counterweight and knife-edge assembly to it and lift the whole bloody deck into the stratosphere in terms of musical performance. I hope I live to see it :lol:

[keiths]

Hi Dave - I knew I would be in trouble from you before I even mentioned this :eyebrows:

I replaced the V-blocks in the arm (though, on inspection, the original ones were pretty much unmarked), but the horizontal bearings exhibited quite a bit of stickyness. I tried to adjust them - even Lenco Heaven has little in the way of information on how to do this properly - but couldn't get anywhere. I asked specfically on LH and the concensus was that the arm wasn't worth the trouble. Also the floppy counterweight stub (even after applying the dental floss trick) didn't inspire confidence - I could hear the piano wire tie creaking and groaning as I was trying to straighten the droop. I also dislike the appearence of the thing with its comedy oversize headshell (I know...), so I decided to cut my losses and buy a cheap Rega RB300.

http://www.simister.com/public/l75.jpg

Sorry... :whippin:

[Spur07]

Thanks again Dave :)

Sounds interesting Keith, which plinth design are you following, the one you can download from LH? May keep in touch if that's ok? Looks like I might have got myself a GL59.

P

[keiths]

As I'm replacing the whole top plate with a PTP ("Peter's Top Plate"), I'm using the cutting template provided by Peter Reinders - so this defines the position of the motor and the bearing (on his design, they are on separate plates) so it was just a case of placing everything on a piece of card and moving stuff around until happy. That's how I came up with 480mm x 380mm - I didn't want to make it bigger than it needed to be.

The rest of the 'design' is rounded corners and black walnut veneer on the top. Haven't decided if I'm going to round off the top edges or not yet.

Will your GL59 come with a plinth? If so, you can use that to base the new cut-out on.

Please do keep in touch.

[Rare Bird]

Dave R
I think one of the main reasons they junk that arm is because that headshell is so unbearably pig ugly to live with :D

[Reid Malenfant]

Dave R
I think one of the main reasons they junk that arm is because that headshell is so unbearably pig ugly to live with :D
Hey Andr'e, I have heard that you don't look at the mantlepiece when poking the fire :lol:

[DSJR]

I give up :rolleyes:

I await my GL78.....

[Reid Malenfant]

I give up :rolleyes:

I await my GL78.....
Sorry Dave :o

[Rare Bird]

I give up :rolleyes:



Cheer up Dave it's only an arm mate :lolsign: