Forsell air reference turntable repair resources

terence8888

New Member
Dec 3, 2020
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Firstly I'm entirely new to this forum and greetings to everyone!

I stumbled upon this forum as I try to get more information on the Forsell Air Ref TT (the one w/o flywheel) and there are members here who have experience in the TT.

I have one that has not been used for over 10 years. I cleaned it up, change the plastic air tubes which have deteriorated and fired it up. I get lots of skips playing the record (i.e. the music keep repeating itself, "sounds like a broken record"). I checked the tonearm and I can feel the friction on the air bearing (with the pump on) which I remember was much smoother last time I used it. I suspect the air bearing had minute amount of oxidation or corrosion and has too much friction for the arm to glide though. The air seems to flow freely and I cleaned everything thoroughly.

Does anyone have any ideas what can be done about this? it will be a pity for such a great TT to go to waste but Forsell told me that they don't support the TT any more because of lack of parts.
 

carolus

Well-Known Member
Dec 20, 2013
115
137
363
Belgium (Brussels)
Firstly I'm entirely new to this forum and greetings to everyone!

I stumbled upon this forum as I try to get more information on the Forsell Air Ref TT (the one w/o flywheel) and there are members here who have experience in the TT.

I have one that has not been used for over 10 years. I cleaned it up, change the plastic air tubes which have deteriorated and fired it up. I get lots of skips playing the record (i.e. the music keep repeating itself, "sounds like a broken record"). I checked the tonearm and I can feel the friction on the air bearing (with the pump on) which I remember was much smoother last time I used it. I suspect the air bearing had minute amount of oxidation or corrosion and has too much friction for the arm to glide though. The air seems to flow freely and I cleaned everything thoroughly.

Does anyone have any ideas what can be done about this? it will be a pity for such a great TT to go to waste but Forsell told me that they don't support the TT any more because of lack of parts.
Hey,
A suggestion/ideas ... start check with:
1 °) The air production (and distribution) system must remain absolutely (100%) free of "dust ... water (condens)... oil"
2 °) All filters (dust&water-&oil) are "OK ??"
3°) all air nozzles ... OK???
4 °) Pressure distribution to TT & TA correct?
5 °) All distribution casings and connections OK? Controle with magnifying -glass (pair of glasses)
6 °) Smoothness of all sliding surfaces?
7°) Others .... !

Good luck.

Karel
(DIY airbearing 16" TT&TA )
 

terence8888

New Member
Dec 3, 2020
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I have check the cleanliness of the air supply. The plastic tubes are new. Cleaned the arm tube with alcohol and each of the air holes is clean. I also cleaned the inside (sliding surface) of the sleeve of the air bearing with alcohol.

I was wondering whether to try and polish then wax the air bearing tube with car polish and wax.
 

carolus

Well-Known Member
Dec 20, 2013
115
137
363
Belgium (Brussels)
I have check the cleanliness of the air supply. The plastic tubes are new. Cleaned the arm tube with alcohol and each of the air holes is clean. I also cleaned the inside (sliding surface) of the sleeve of the air bearing with alcohol.

I was wondering whether to try and polish then wax the air bearing tube with car polish and wax.
Aie, aie, aie ....
+ See point N° 3 ... "all air nozzles OK"?
+ Check all nozzles (TT & TA) with correct air pressure & smoke-tester (or cigarette ... cigar ... very sorry for this suggestion)
(& re-check all filters after 10 ears, please .... & point 5°)
Karel
 
Jan 18, 2012
2,323
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Drobak Norway
with my Airtangent Reference after long idle time the only thing that really cleans up the airflow in the bearing is to slide back and forth with some force and the residue or whatever will wear off.....the tube is so hard it´s no problem....
 

Lagonda

VIP/Donor
Feb 3, 2014
3,424
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Denmark
I owned a Forsell arm for years. The needle tip sized small air holes on the air-manifold can get clogged by gunk, take a large syringe and fill it with propyl alcohol. Attach a piece of tubing to the syringe and the end of the air-supply manifold. Hold the whole thing into a bucket and start pushing alcohol trough the system, refill the syringe and repeat, 10- 15 min normally does the trick, it will slowly open up all the little holes again. I do this to my Maplenoll arm once a year, and it always solves flow problem. Check with a magnifying glass if the coating on the air manifold has gotten deeply scratched, if yes, you have a more serious problem. F53C9E7E-1F23-413A-8E40-7178B2973D03.jpeg F5503FB5-4924-4153-8044-4F31959900F2.jpeg
 
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carolus

Well-Known Member
Dec 20, 2013
115
137
363
Belgium (Brussels)
I have check the cleanliness of the air supply. The plastic tubes are new. Cleaned the arm tube with alcohol and each of the air holes is clean. I also cleaned the inside (sliding surface) of the sleeve of the air bearing with alcohol.

I was wondering whether to try and polish then wax the air bearing tube with car polish and wax.
Another personal experience with (my DIY air bearing TT) and with nozzles diameter 0.2mm as an additional option:

0 °) Necessary technical skills ...
1 °) Take a multi-core electrical (flexible) cable (with ultra fine cores ... the finest)
2 °) cut a small length of ultra-thin wire from the strand (smaller or equal to the drill diameter) ...
3 °) check with smoke detector ... for suspected "clogged" nozzles ...
4 °) use the method of "Lagonda" (Isopropyl alcohol) to remove the clogged/debris nozzle (s) by tinkering with the ultra-fine wire (with good diameter) through the nozzle .... (& fingerspitzengefühl!)

Always succeeded @ home
Succes.
Karel

(one musical note @ Lagonda ... chapeau)
 
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Nov 26, 2020
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Any members have the specs for the power supply controller to the motor, my controller transformer went out yesterday and i can’t seem to get measurements for the secondary of the toroidal reading. Please advise?
 

terence8888

New Member
Dec 3, 2020
4
0
1
60
Thanks for all the great replies. I've managed to get a manufacturer in Poland to look at it and it's being repair right now. The problem seems to be more than just clogged holes. Will report back.

On the power supply controller. I opened it up (a cheap plastic box sealed with glue) so no chance of repairing once opened. Inside it's basically a 220v to 110v transformer for the TT motor. And there is a small 220v to 5v (or maybe 12V) to operate a relay which in turn operates the pump (runs on 220v). Not sure what VA the motor transformer is but would not be much more than 100VA judging by the size. It has a EMI filter which Forsell blacked out the serial number but is a £5 piece of component. Lastly it has a thermistor for the soft start of the motor transformer. All in all not impressed by the quality TBH. The relay was hot glued to the box and came of making a rattle.

Given the age, my motor is shot. Is yours still OK? Not sure how to get a replacement and more importantly how to get the pulley out to fit the new motor.
 

Lagonda

VIP/Donor
Feb 3, 2014
3,424
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Denmark
Thanks for all the great replies. I've managed to get a manufacturer in Poland to look at it and it's being repair right now. The problem seems to be more than just clogged holes. Will report back.

On the power supply controller. I opened it up (a cheap plastic box sealed with glue) so no chance of repairing once opened. Inside it's basically a 220v to 110v transformer for the TT motor. And there is a small 220v to 5v (or maybe 12V) to operate a relay which in turn operates the pump (runs on 220v). Not sure what VA the motor transformer is but would not be much more than 100VA judging by the size. It has a EMI filter which Forsell blacked out the serial number but is a £5 piece of component. Lastly it has a thermistor for the soft start of the motor transformer. All in all not impressed by the quality TBH. The relay was hot glued to the box and came of making a rattle.

Given the age, my motor is shot. Is yours still OK? Not sure how to get a replacement and more importantly how to get the pulley out to fit the new motor.
You should go for a complete modern solution for this excellent TT.
This package designed by Bill Carlin from Phoenix Engineering would do the trick :
 

microstrip

VIP/Donor
May 30, 2010
20,806
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Portugal
Thanks for all the great replies. I've managed to get a manufacturer in Poland to look at it and it's being repair right now. The problem seems to be more than just clogged holes. Will report back.

On the power supply controller. I opened it up (a cheap plastic box sealed with glue) so no chance of repairing once opened. Inside it's basically a 220v to 110v transformer for the TT motor. And there is a small 220v to 5v (or maybe 12V) to operate a relay which in turn operates the pump (runs on 220v). Not sure what VA the motor transformer is but would not be much more than 100VA judging by the size. It has a EMI filter which Forsell blacked out the serial number but is a £5 piece of component. Lastly it has a thermistor for the soft start of the motor transformer. All in all not impressed by the quality TBH. The relay was hot glued to the box and came of making a rattle.

Given the age, my motor is shot. Is yours still OK? Not sure how to get a replacement and more importantly how to get the pulley out to fit the new motor.

As far as I remember the Forsell Reference motor was a synchronous motor similar to those used in many turntables - they usually can be operated at 110V with a phase capacitor - the Lingo power supply, for example, was working this way. These motors are robust - are you sure yours is faulty? Did you measure the resistance of the coils?

If you supply the motor with an adjustable frequency the pulley diameter is not critical, as long it is not too different. I have successfully driven the Forsell with several external motors, including the Michell Girodeck, as the airbearing flywheel motor often become crazy! And yes, their electronics built quality is miserable. I was really shocked when I opened the Forsell Air bearing CD transport!
 

terence8888

New Member
Dec 3, 2020
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The motor still turns but makes a clicking noise. I sent the motor to the Polish manufacturer (Pre-Audio If anyone is interested). They say the bearing is gone. They are trying to adapt their own motor to fit into my TT as well as getting the arm fixed. I'm hopeful but still waiting for the end result. 2 questions:

1 Do you know whether the platter can be removed from the main bearing? I've never succeeded in doing so.
2. Where can I buy the belt? It's supposed to be a vpi but there seems to be different lengths of vpi belts.

Many thanks!
 
Nov 26, 2020
12
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My unit is made to work in the US. The transformer that is dead is the main transformer. I am assuming it’s a 117v primary and 220v secondary, i could be wrong. I attached a pix of the actual transformer, which got really hot.
 

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Nov 26, 2020
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Since the transformer is dead, i can’t get a reading, any members have the actual reading of this transformer if they can post what the secondary of this transformer? I need a replacement. Thanks!
 

uptick

Member
Oct 2, 2021
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0
6
62
Since the transformer is dead, i can’t get a reading, any members have the actual reading of this transformer if they can post what the secondary of this transformer? I need a replacement. Thanks!
I just took apart a working ~30 year old Forsell TT power supply box. The kit came with 220V connections. The power supply box has a 30~40VA (?)220/120 V transformer, two standard line filters, a "Copenhagen Magnetics" filter PCB with common mode chokes etc and 3 burned out RIFA (?) caps, a much smaller 220V primary "12V" transformer, rectifier, an electrolytic cap.
The only value I see of this box is the 12V relay circuit to turn on the pump AC power supply. The 220V circuit has no use in the US.
The original Hiblow pump has since long time lost much of its output, and have been replaced with another kit from the same manufacturer, along with the tubing.
AC EMI Line filters for the air pump and the motor have doubtful value as these are in no way connected to the signal path. Seems like audiophile OCD, not engineering. Moreover, those EMI line filters need a ground to be effective, and there are no switching power supplies involved, so why?
The plastic box will be discarded with a customized power strip that will include a relay, actuated that switch on the TT to use an alternative 12V supply.
The motor is clearly a 600 rpm type, probably a HURST. You don't need a 100W power supply for a (max)10W motor with a light load. I have not measured the current draw, yet, I'd expect it to be very low running, maybe under 1 watt.
The system has been upgraded with new two air pumps, two flow gages/controllers for individual platter and tonearm control, and a variable speed controller with 0.01Hz resolution. (The original pressure-surplus distribution setup without gages was kind of a joke.)
It sounds and works good.
 

Florian

Well-Known Member
Jun 26, 2016
74
124
163
Switzerland
Hello,
i am picking up my Forsell Air Reference MK2 on Thursday. Does anybody have the tonearm weight, i assume i am looking for a middle to high compliance cartridge? Any pointers would be well received :) Thanks
 

uptick

Member
Oct 2, 2021
2
0
6
62
I would use a high compliance cartridge, as there is very little mass in the tonearm and friction is nil. Goldring E3 20mm/N sounds fine. Cheap too.

 

orfeo_monteverdi

Well-Known Member
Jan 16, 2015
99
156
265
Europe
The motor still turns but makes a clicking noise. I sent the motor to the Polish manufacturer (Pre-Audio If anyone is interested). They say the bearing is gone. They are trying to adapt their own motor to fit into my TT as well as getting the arm fixed. I'm hopeful but still waiting for the end result. 2 questions:

1 Do you know whether the platter can be removed from the main bearing? I've never succeeded in doing so.
2. Where can I buy the belt? It's supposed to be a vpi but there seems to be different lengths of vpi belts.

Many thanks!
[please forgive my poor english]

So, Terence, what is the outcome? Did the Polish manufacturer Pre-Audio managed to help/repair it?
 

Guscom

Well-Known Member
Oct 22, 2018
33
7
88
62
qualcuno ha il manuale del giradischi forsell air reference da potermi inviare ? grazie
gelosuora
Ciao, mi pare di capire che sei in Italia, che versione hai? Mandami qualche foto in pvt, vedo di aiutarti
 

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