Any Forsell Air Reference LTD owners here?

[Ki Choi]

Hi,

Looking for advice on how to improve air system from Forsell gurus.

I would like to know what would be the best air pump(s) for noise and performance for both arm and platter along with regulator(s) and airline choices, etc.

Thanks,
Ki

 

[microstrip]

Hi,

Looking for advice on how to improve air system from Forsell gurus.

I would like to know what would be the best air pump(s) for noise and performance for both arm and platter along with regulator(s) and airline choices, etc.

Thanks,
Ki

Ki,

I am still using the three original pumps and the several surge tanks and filters that were supplied with my AirForse one. Athur Salvatore writes about an alternative pump and air system in his site: http://www.high-endaudio.com/RC-Tables.html

For Improved Air Flow- I use 3 low-pressure, high-flow pumps for the tonearm, and 2 low-pressure, high-flow pumps for the platter. Each group has its own dedicated regulator, with 1% variability down to 1 PSI. I use the Schrader-Bellows models. The tonearm supply also uses the surge tank that comes with the turntable, the platter does not.

 

[Ki Choi]

high-flow pumps for the tonearm, and 2 low-pressure, high-flow pumps for the platter. Each group has its own dedicated regulator, with 1% variability down to 1 PSI. I use the Schrader-Bellows models. The tonearm supply also uses the surge tank that comes with the turntable, the platter does not.

thanks for your response.

It would help to have numbers associated to what "high-flow" and "low pressure" mean. As I understand it, Forsell supplied one Japanese made 6 liter/min flow rate linear air pump that is very quiet at 31 dBA and have the air supply divided between tonearm and platter air bearing at the turntable. I wonder what it means to have high-flow...is it more than 6 L/min?

If you can list the pump make and model along with specs on your air surge tank(s) that you are using with good results, I would appreciate it. Photos of the pump ID label and the air tank would be nice too...

Ki

 

[microstrip]

thanks for your response.

It would help to have numbers associated to what "high-flow" and "low pressure" mean. As I understand it, Forsell supplied one Japanese made 6 liter/min flow rate linear air pump that is very quiet at 31 dBA and have the air supply divided between tonearm and platter air bearing at the turntable. I wonder what it means to have high-flow...is it more than 6 L/min?

If you can list the pump make and model along with specs on your air surge tank(s) that you are using with good results, I would appreciate it. Photos of the pump ID label and the air tank would be nice too...

Ki

I attach a photo of the original surge tanks (nice name for some cheap plastic jars) - the double ones are for the platter and flywheel, the triple one for the arm. My turntable is the AirForce one and came with three SPP6Ga pumps - 6lpm /9.8 kPa - one for each part. One of the surge tanks of each block gets the air from a filter and supplies it to the pump input. IMHO if you use large surge tanks and pressure regulators the type of pump is not too important any more, as long as you have some excess of air flow to allow adjustment. enough. Do you need the Forsell instructions to adjust the pressure?

 

[Ki Choi]

Thanks again for your speedy response. A scanned copy of the manual would be nice.

I agree if I can get an industrial surge tank with a quiet compressor and have ability to regulate and adjust output flow, I wouldn't have to have fancy plastic jars. Mine that is a Forsell Air Reference Limited Edition with no flywheel and did come with one three part surge tank. The single air supply was to be divided in the turntable for tonearm and the air bearing for platter with a knob.

 

[microstrip]

Thanks again for your speedy response. A scanned copy of the manual would be nice.

I agree if I can get an industrial surge tank with a quiet compressor and have ability to regulate and adjust output flow, I wouldn't have to have fancy plastic jars. Mine that is a Forsell Air Reference Limited Edition with no flywheel and did come with one three part surge tank. The single air supply was to be divided in the turntable for tonearm and the air bearing for platter with a knob.

I have just sent a copy of the manual by mail. The motor of the Reference is very good, but as far as I remember the power supply is a poor design - as was the one of the Air Force one.
Some people use the VPI double flywheel with success, and we must remember that one of the more expensive German made turntables just uses a Revox B77 moor with its controller to drive the platter through a pulley and belt system. The whole system weights around 400 lbs ...

 

[Ki Choi]

One more question: in controlling all three SPP6GA pumps, do all three pumps getting power from the single outlet from the power supply module controlled from the turntable switch? I have seen photo of two SPP6GA pumps tied together in input power and plugged into the power supply module cord with 220V receptacle.

If I were to upgrade the pump with a different model with 20 liter/min capacity to feed a real surge tank, I need to make sure the controlled power can handle the load:



Model: AL-15A
Voltage: 115V or 230V
Rate Pressure: 10 kPa - 1.4 psi
Rate Performance: 20 lpm, 0.7 cfm
Rated Input Power: 26w
Noise Level: 29 dB
Fitting Size: 1/8" FPT

 

[Ki Choi]

I have just sent a copy of the manual by mail. The motor of the Reference is very good, but as far as I remember the power supply is a poor design - as was the one of the Air Force one.
Some people use the VPI double flywheel with success, and we must remember that one of the more expensive German made turntables just uses a Revox B77 moor with its controller to drive the platter through a pulley and belt system. The whole system weights around 400 lbs ...

Did you mean postal mail or email?
If you have a link for the German mod with Revox motor (assume capstan motor) to driver the platter, I would be interested. I have a lot better capstan motor/control options like Studer A80 capstan motors with varispeed to get it perfect!

 

[microstrip]

Did you mean postal mail or email?
If you have a link for the German mod with Revox motor (assume capstan motor) to driver the platter, I would be interested. I have a lot better capstan motor/control options like Studer A80 capstan motors with varispeed to get it perfect!

The manual pages were sent to your comcast.net email account. I only have this link to a review of the Apolyt turntable - sorry it is in German! http://www.knipschild.net/Brakemeier/apolyt.htm

 

[microstrip]

One more question: in controlling all three SPP6GA pumps, do all three pumps getting power from the single outlet from the power supply module controlled from the turntable switch? I have seen photo of two SPP6GA pumps tied together in input power and plugged into the power supply module cord with 220V receptacle.

If I were to upgrade the pump with a different model with 20 liter/min capacity to feed a real surge tank, I need to make sure the controlled power can handle the load:



Model: AL-15A
Voltage: 115V or 230V
Rate Pressure: 10 kPa - 1.4 psi
Rate Performance: 20 lpm, 0.7 cfm
Rated Input Power: 26w
Noise Level: 29 dB
Fitting Size: 1/8" FPT

When I got my Forsell with the pumps control unit I could not resist opening it. It had a small toroid transformer, a diode bridge and a capacitor to supply DC power for the motor controller and a lot of 220V mains power filters - the only components in series with the pumps were some large Schaffter type mains filters. We could ask why the pumps needed such RF filtering! I will take a photo for you.

 

[Ki Choi]

I attach a photo of the original surge tanks (nice name for some cheap plastic jars) - the double ones are for the platter and flywheel, the triple one for the arm. My turntable is the AirForce one and came with three SPP6Ga pumps - 6lpm /9.8 kPa - one for each part. One of the surge tanks of each block gets the air from a filter and supplies it to the pump input. IMHO if you use large surge tanks and pressure regulators the type of pump is not too important any more, as long as you have some excess of air flow to allow adjustment. enough. Do you need the Forsell instructions to adjust the pressure?

Can you tell me the airline and fitting size data for the fitting shown in your surge tanks?

I am not sure if I can source correct metric type air fittings readily. As I am having to learn the pneumatic world, we use:

NPT – National (American) Pipe Tapered Thread

and Europe uses one of the below thread standards:

BSPT (R) – British Standard Pipe Tapered Thread
BSPP (G) – British Standard Pipe Parallel Thread

By the looks of it, the airline is about 6mm O.D.

Thanks, Francisco.

Ki

 

[Peter Breuninger]

Ki, let's see pics of the table.

 

[Ki Choi]

Ki, let's see pics of the table.

Well...Peter, she's not quite ready for primetime, yet - still primping and getting ready to sing at her best - soon...

 

[Peter Breuninger]

You are such a tease

 

[rockitman]

You are such a tease

looks like a tweakers delight !

 

[mep]

I count at least 26 places you could put Stillpoints from that photo above. A mere $18,200 to tweak it out.

 

[rockitman]

I count at least 26 places you could put Stillpoints from that photo above. A mere $18,200 to tweak it out.

yes, those very basic target stands are inadequate. I still have one of those from the 90's

 

[mep]

yes, those very basic target stands are inadequate. I still have one of those from the 90's

I have one from the 1980s as well. I still use it to sit one of my subs on. I thought it was the bomb when I first bought it.

 

[rockitman]

I have one from the 1980s as well. I still use it to sit one of my subs on. I thought it was the bomb when I first bought it.

I thought it was all you would ever need construction wise back in the day. They were a bargain. I keep a RTR machine and a King Cello pre on one still.

 

[microstrip]

looks like a tweakers delight !

Yes, it is. If you use a double belt as shown you can even use two different types of dental floss! . Although when you master it, it becomes logical and simple to use.