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Re: Meltrope II servicing

Posted: Thu Nov 19, 2020 2:56 am
by Ahmed
Inigo wrote:Could be... Some time... and I'll go back to it!
My 5a and 5bs sing beautifully, but one of them needed extensive tinkering until I got 'that'sound... We could talk a long hour on my experiences with these sbx...
Indeed! That's half the fun I think!

@Orchorsol; here are close ups of the Wild modifications as promised. Soundbox all done for now, but head to head I prefer the III. This one sounds fairly brighter which lends itself to some records, but the III is much more well rounded to my ears

Re: Meltrope II servicing

Posted: Fri Nov 20, 2020 9:59 am
by Inigo
So Wild simply added leather pads between the spring and the case, and between the spring and the balls.... Interesting, for this increases the compliance of the needlebar, and silences any rattling coming from there, allowing to install the springs with a lower pressure on the needlebar plate. I did a similar thing to an exhibition, adding thin rubber pieces at the knife supports and at the spring screws too. I also relaxed the pressure on the back of the sbx, by releasing the screws until the pressure on the tube gaskets was as low as possible, but still airtight. Then I sealed the screws in that loosened position with Elmer's glue, and I also sealed all around the backplate to the sbx body. This, together with a glass diaphragm, and an elbow connector to correct the gooseneck tracking error, and the sbx sounds pretty good, especially with electrical records. What I think is that the horn (it's a French HMV tabletop similar to the Victrola VI) now it's too short and small for such a powerful exhibition sbx, and acoustic records sound too loud...
IMG_20200524_130816[1].jpg

Re: Meltrope II servicing

Posted: Fri Nov 20, 2020 11:34 am
by HMV130
Ahmed wrote:
Inigo wrote:Could be... Some time... and I'll go back to it!
My 5a and 5bs sing beautifully, but one of them needed extensive tinkering until I got 'that'sound... We could talk a long hour on my experiences with these sbx...
Indeed! That's half the fun I think!

@Orchorsol; here are close ups of the Wild modifications as promised. Soundbox all done for now, but head to head I prefer the III. This one sounds fairly brighter which lends itself to some records, but the III is much more well rounded to my ears
Thank-you for sharing the pictures. Always interesting see a Wild modified Meltrope. Unfortunately I think that someone already tinkered with it - the springs have been compressed to a point that they have been bend. Hope you will be able to restore their original shape without any "unpleasant consequences"!

I also suggest you to use the right gaskets. New ones are available in different thickness and softness. Specifically Meltrope mod. II soundboxes need a slightly thicker gaskets, please consider the attached picture.

Finally you should consider to interpose some rubber material between the screws and springs - I did this to one of my Meltrope soundboxes and the result in terms of sound reproduction is quite interesting.

Re: Meltrope II servicing

Posted: Fri Nov 20, 2020 3:57 pm
by Ahmed
HMV130 wrote:
Thank-you for sharing the pictures. Always interesting see a Wild modified Meltrope. Unfortunately I think that someone already tinkered with it - the springs have been compressed to a point that they have been bend. Hope you will be able to restore their original shape without any "unpleasant consequences"!....
Many thanks for your advice! As I'm not entirely pleased with the sound yet, there's more tinkering to be done. Not attempted to straighten the bars yet, but they seem solid enough to bend back o issues (I hope!)

Re: Meltrope II servicing

Posted: Fri Nov 20, 2020 4:49 pm
by Orchorsol
Many thanks indeed for showing the Wild additions Ahmed!

Re: Meltrope II servicing

Posted: Fri Nov 20, 2020 5:14 pm
by Ahmed
You're very welcome Andy! After further tinkering this evening I think I finally like the sound of it :) video soon

@Indigo; that's one seriously modified Exhibition! Would love to hear what it sounds like. I do wonder even with the modifications, how does it compare to a No.4 for instance with its much bigger diaphragm?

Re: Meltrope II servicing

Posted: Sat Nov 21, 2020 2:24 pm
by old country chemist
Hello Ahmed, good to see you are experimenting with the "Wild" soundbox conversion. I think it does make a difference, and improves the sound-it has done so for me. The fiddly bit was making the leather washers! I used some minute rubber washers between the stylus plate and the ball bearings. I just put a spot of glue on the rubber washers and they stayed on the stylus plate during assembly. I have still to add insulation to the soundbox front guard, which might be tricky. I think Mr. Wild used sealing wax for that job.
I did see the "Sonat" soundbox for sale a while back on e bay. Nicely made. I have an advertisement somewhere for a range of "Algraphone" machines. the most expensive-£100 IN 1925!! I agree with some of the others that the aluminium plate is probably screwed in. I thought at first that it would be an "interference" fit, but Alfred Graham would probably not stooped low enough to contemplate that mode of assembly. I wish you well, and hope it comes apart all right.
Talking of Meltrope gaskets. I always imagined the no1 no1a and the 2 having the ordinary white "exhibition" type gasket, but the Meltrope 3 had a black rubber gasket of 3.2mm diameter.
It can be challenging taking sound reproducers to piece and renovating them. I found that when I recently bought an "Orchorsol" sounbox. It was not the dismantling, it was the putting it all back together that was a whole new experience for me!

Re: Meltrope II servicing

Posted: Sat Nov 21, 2020 5:05 pm
by Ahmed
old country chemist wrote:Hello Ahmed, good to see you are experimenting with the "Wild" soundbox conversion. I think it does make a difference, and improves the sound-it has done so for me. The fiddly bit was making the leather washers! I used some minute rubber washers between the stylus plate and the ball bearings. I just put a spot of glue on the rubber washers and they stayed on the stylus plate during assembly. I have still to add insulation to the soundbox front guard, which might be tricky. I think Mr. Wild used sealing wax for that job.
I did see the "Sonat" soundbox for sale a while back on e bay. Nicely made. I have an advertisement somewhere for a range of "Algraphone" machines. the most expensive-£100 IN 1925!! I agree with some of the others that the aluminium plate is probably screwed in. I thought at first that it would be an "interference" fit, but Alfred Graham would probably not stooped low enough to contemplate that mode of assembly. I wish you well, and hope it comes apart all right.
Talking of Meltrope gaskets. I always imagined the no1 no1a and the 2 having the ordinary white "exhibition" type gasket, but the Meltrope 3 had a black rubber gasket of 3.2mm diameter.
It can be challenging taking sound reproducers to piece and renovating them. I found that when I recently bought an "Orchorsol" sounbox. It was not the dismantling, it was the putting it all back together that was a whole new experience for me!
Thank you sir :) Just finished the soundbox this evening and here it is singing https://youtu.be/fin_lGoAM2c

Very pleased with the result. I didn't see any sealant on the faceplate feet, but packed them in with beeswax to avoid any rattling. The springs straightened up no issues, and I used beeswax to seal the screws rather than rubber washers. Final ingredient is STP oil on the ball bearings; that's my secret ingredient and does a beautiful job at eliminating any metal on metal buzz without restricting movement

Thanks for the advice re the Sonat; it'll drive me mad for a bit until it's opened, but I shall get there eventually! Next step even I have some time is making a rig with some pins to give me some more leverage to open it up

Re: Meltrope II servicing

Posted: Sat Nov 28, 2020 8:08 am
by Inigo
Ahmed wrote: .... @Indigo; that's one seriously modified Exhibition! Would love to hear what it sounds like. I do wonder even with the modifications, how does it compare to a No.4 for instance with its much bigger diaphragm?
@Ahmed, and all,
That modified Exhibition sounds good with electrical recordings, but I find it a bit too strong with acoustics. I'm not yet well acquainted with these sbxs. Still I have to experiment further. I own three of them, the original hmv with mica diaphragm, which I yet have to fine tune, this triangular hole much altered, and another unaltered with triangular hole.
The tracking correcting elbow is attached to the back rubber, so changing it I can install it on any of them three, to avoid stripping off the records. I will install it definitely on the one that results better. The altered one has been altered again, for the other day, apropos the messages, I checked the thin rubber washers and they were perished. Besides that, they kill the high treble a bit, so next experiments will try to cope with that.
BTW, them three sound great when using bamboo needles!