If the version you are building is rev.3 it is 820pF, otherwise it would be 680pF. I recommend the last revision over the others.
Yes those are good caps.
Half the people who said they wanted boards have paid for the EQ PCB so far, those will go out tomorrow morning along with any that are paid in the interim. The balance will go out once once everyone else has paid for the boards. It is snowy and icy here and I'm not making repeated trips to the Post Office to ship boards. If you want your boards soon please pay before 9AM tomorrow!
Thanks!
Thanks!
Here is what I am playing with these days, a recently acquired rather well used ET-2 with a magnesium arm wand. This seems to be about the best match up I have found for the Panasonic EPC-451C phono cartridge.
I purchased a Silentaire Super Silent air compressor to replace the large WISA air pump which is noisy and provides rather inconsistent air pressure. This will give me the opportunity to experiment with the effect of higher air pressure as well. The current pump delivers air pressure depending on the phase of the moon, and some unknown karmic alignment (probably the line voltage and temperature down here - higher when it is chilly) the arm sounds better above 4.5 psi than it does below it, but pressure varies from a low of 3.6 psi to high of almost 5 psi. Tonight the pressure is a mediocre 4.1 psi. The new compressor will permit operation at any pressure the arm will tolerate, but ideally suspected to be in the range of 6 - 7 psi.
I'm still experimenting with the set up and will soon purchase a couple of the available upgrades.
I'm pretty sure now I am going to get a second one to go on the other table.
I purchased a Silentaire Super Silent air compressor to replace the large WISA air pump which is noisy and provides rather inconsistent air pressure. This will give me the opportunity to experiment with the effect of higher air pressure as well. The current pump delivers air pressure depending on the phase of the moon, and some unknown karmic alignment (probably the line voltage and temperature down here - higher when it is chilly) the arm sounds better above 4.5 psi than it does below it, but pressure varies from a low of 3.6 psi to high of almost 5 psi. Tonight the pressure is a mediocre 4.1 psi. The new compressor will permit operation at any pressure the arm will tolerate, but ideally suspected to be in the range of 6 - 7 psi.
I'm still experimenting with the set up and will soon purchase a couple of the available upgrades.
I'm pretty sure now I am going to get a second one to go on the other table.
Attachments
Congratulations on the new arm!
I don't know what kind of air bearing used in the ET-2 arm. If you purchased a Silentaire compressor, its filter is not adequate since the pump uses oil. Small amount of oil may be pumped into airline. On my air bearing arm, I am using 5 stages of filter. For your arm, I think you need at least to add two more stages. One is coalescing with 0.3 micron filter element and 2nd one is mist separator with 0.01 micron filter element. I use one made by SMC.
Another problem is it is better to power the compressor from different main power line from your audio gear. Otherwise, whenever the compressor kicks in, it will cause pop noise. I have no choice but to use same power main as the audio system. Kuzma uses a solid state relay. I tried it. It doesn't work.
I don't know what kind of air bearing used in the ET-2 arm. If you purchased a Silentaire compressor, its filter is not adequate since the pump uses oil. Small amount of oil may be pumped into airline. On my air bearing arm, I am using 5 stages of filter. For your arm, I think you need at least to add two more stages. One is coalescing with 0.3 micron filter element and 2nd one is mist separator with 0.01 micron filter element. I use one made by SMC.
Another problem is it is better to power the compressor from different main power line from your audio gear. Otherwise, whenever the compressor kicks in, it will cause pop noise. I have no choice but to use same power main as the audio system. Kuzma uses a solid state relay. I tried it. It doesn't work.
I have several filters, but will look at adding another one based on your recommendations.
I have entirely separate power for the compressor so EMC issues won't be an issue.
I am not sure where I am going to put the compressor in the long term, but at least initially it will be located in the man cave bathroom which is the only separate space down here with a door.
I have entirely separate power for the compressor so EMC issues won't be an issue.
I am not sure where I am going to put the compressor in the long term, but at least initially it will be located in the man cave bathroom which is the only separate space down here with a door.
Nice arm ! Been using these a long time and the adjustments are priceless
I have the pumps in another room and simple drilled a small hole thru the drywall for the air tubing.
You might want to build surge tanks ahead of the pump to smooth pulses and the longer the tubing the better.
I used 3” Black pvc water tubing and made 2 different length tanks in series stuffed with polyester fill.
When I transferred the 451 from the JVC ql-10 DD / stock arm to the Sota vacuum table /
Stock ET2, the depth increased about 40% with more air and openness all around Along with more separation from speaker location cues.
The short arm ET2 version is still awaiting another vacuum platter TT build ,When I get the time..
Regards
David
I actually tried that first, but because of the design of the TD 124 the height adjustment was completely bottomed out and I could not get a good VTA adjustment. In fact the record is fairly close to the center of the tube as currently set up.
Bruce T recommended I remove the spacer weight I am currently using, but that did not work out well. So far this seems to be the best overall compromise.
It's early times and the arm will be coming off for a mounting post upgrade and I can look at everything again at that point. I can probably get it a bit lower.
It will track warped records without any drama that my others won't.
Bruce T recommended I remove the spacer weight I am currently using, but that did not work out well. So far this seems to be the best overall compromise.
It's early times and the arm will be coming off for a mounting post upgrade and I can look at everything again at that point. I can probably get it a bit lower.
It will track warped records without any drama that my others won't.
Well, I took a combination of your's and Bruce T's advice. 
He recommended I remove the cartridge spacer/weight, and you suggested I try to lower the pivot point.
I was able to do both.
I was able to lower the arm perhaps a total of 300 mils after removing the spacer which is about 200 mils thick.
This results in a cartridge mass of 3.5gms which Bruce indicated was just fine with my magnesium arm tube.
I also removed about 40 gms of counterweight mass, will see what effect that has on bass response since the counterweight ended up in almost the same spot as before so effective mass has decreased about 50% - the mass is all lead now which may just be audible.
The VTA adjuster on this arm only works properly from 0° to +2° and -1° to -2° , unfortunately in the range of 0° to -1° the arm rocks and is no longer level, I can straighten it once adjusted and it will stay, still this sort of isn't the point. Given the general condition of this arm I doubt this is going to be reparable, and so far it can't be adjusted out. It think the machined surfaces are worn in that area as you definitely feel it as you adjust VTA and you can see the arm wobble a bit. The lever force is consistent to you hit this spot and then decreases noticeably and the arm wobbles through this spot, once past this spot on either side it returns to level. It can be straightened manually and will stay put. I suspect at some point in life it was badly misadjusted and was operated frequently over this range.
VTA adjustment is much less critical for the 451C on this arm than was the case for the Souther, so while it's disappointing in practice it has not proved to be much of an issue at all. VTA changes due to record thickness are in my experience not necessary or noticeably beneficial when attempted with this arm. I am using a Panasonic OEM Shibata modified as discussed earlier. Reproduction is extremely clean.
Something else worth mentioning is the cartridge tracks fine at 2.5gms or even less on this arm.
He recommended I remove the cartridge spacer/weight, and you suggested I try to lower the pivot point.
I was able to do both.
I was able to lower the arm perhaps a total of 300 mils after removing the spacer which is about 200 mils thick.
This results in a cartridge mass of 3.5gms which Bruce indicated was just fine with my magnesium arm tube.
I also removed about 40 gms of counterweight mass, will see what effect that has on bass response since the counterweight ended up in almost the same spot as before so effective mass has decreased about 50% - the mass is all lead now which may just be audible.
The VTA adjuster on this arm only works properly from 0° to +2° and -1° to -2° , unfortunately in the range of 0° to -1° the arm rocks and is no longer level, I can straighten it once adjusted and it will stay, still this sort of isn't the point. Given the general condition of this arm I doubt this is going to be reparable, and so far it can't be adjusted out. It think the machined surfaces are worn in that area as you definitely feel it as you adjust VTA and you can see the arm wobble a bit. The lever force is consistent to you hit this spot and then decreases noticeably and the arm wobbles through this spot, once past this spot on either side it returns to level. It can be straightened manually and will stay put. I suspect at some point in life it was badly misadjusted and was operated frequently over this range.
VTA adjustment is much less critical for the 451C on this arm than was the case for the Souther, so while it's disappointing in practice it has not proved to be much of an issue at all. VTA changes due to record thickness are in my experience not necessary or noticeably beneficial when attempted with this arm. I am using a Panasonic OEM Shibata modified as discussed earlier. Reproduction is extremely clean.
Something else worth mentioning is the cartridge tracks fine at 2.5gms or even less on this arm.
Sounds like a complete disassembly is required as I can’t imagine someone using it this much for a dead spot to occur in the VTA adjustment range but anything’s possible.
There should be no wobble either. Something’s amiss
The VTA channel it slides in should be greased and the set screw not so tight to bind its travel.
Pulling I apart and checking and greasing the gearing VTA might show grit of some kind.
Nothing on this arm should be overtightened BTW.
Regards
David
There should be no wobble either. Something’s amiss
The VTA channel it slides in should be greased and the set screw not so tight to bind its travel.
Pulling I apart and checking and greasing the gearing VTA might show grit of some kind.
Nothing on this arm should be overtightened BTW.
Regards
David
I will take a look at some point, and see if there is anything at all I can do. My sense is the damage has been done, but actually looking at it would be a good idea. I would characterize it as a partial deadspot as the spiral cut gear does not maintain even contact with the running surface on one side over the stated number of degrees.
The VTA adjustment isn't really that useful with these cartridges to my surprise. I guess the very short arm geometry of the Southers greatly aggravates VTA sensitivity. I can't tell much of a difference over the 4° adjustment range so I am not going to worry about it.I also don't want to make it worse while I am so early on the learning curve. This arm even with this issue is an absolutely massive improvement over anything I have ever owned.
This arm gives me perspective, and levels of detail I've not heard before. It really helps the 451C strain gauge cartridge shine, it is a very, very good match.
I have to admit a certain amount of angst over the fact that I deliberately avoided these arms for years because of their reputation for being difficult to set up and use. Until the first Souther landed here something like a year ago I had not considered a linear tracker. I instead stuck to the tried and true pivoted arms and have had some expensive ones in recent years that did not make me happy. I guess 1950s MC cartridges and the arms made to play them might not be the solution I am looking for. Something about dying during the last couple of cuts on every album I have ever owned, both the Southers I own and the ET-2 are completely free of inner groove distortion. The ET-2 is considerably cleaner sounding than anything else I own, the Southers are the next closest thing, but are much fussier about everything and ultimately even with lots of mods only get close to this arm. (Nothing else I own does)
The VTA adjustment isn't really that useful with these cartridges to my surprise. I guess the very short arm geometry of the Southers greatly aggravates VTA sensitivity. I can't tell much of a difference over the 4° adjustment range so I am not going to worry about it.I also don't want to make it worse while I am so early on the learning curve. This arm even with this issue is an absolutely massive improvement over anything I have ever owned.
This arm gives me perspective, and levels of detail I've not heard before. It really helps the 451C strain gauge cartridge shine, it is a very, very good match.
I have to admit a certain amount of angst over the fact that I deliberately avoided these arms for years because of their reputation for being difficult to set up and use. Until the first Souther landed here something like a year ago I had not considered a linear tracker. I instead stuck to the tried and true pivoted arms and have had some expensive ones in recent years that did not make me happy. I guess 1950s MC cartridges and the arms made to play them might not be the solution I am looking for. Something about dying during the last couple of cuts on every album I have ever owned, both the Southers I own and the ET-2 are completely free of inner groove distortion. The ET-2 is considerably cleaner sounding than anything else I own, the Southers are the next closest thing, but are much fussier about everything and ultimately even with lots of mods only get close to this arm. (Nothing else I own does)
It is a pretty substantial improvement over anything I have ever owned, and while I am less confident about stating that it is probably better than anything else I've heard it is likely to be true given the comparatively limited exposure I've had.
I've already decided I am going to get another, the premise being you probably can't have too much of a good thing..
I've already decided I am going to get another, the premise being you probably can't have too much of a good thing..
Kevin,
It seems to me that you are hooked on air bearing arm now.👍
Btw, do you have any solution to eliminate pop noise for Silentaire compressor? I am using two solid state relays at the air pressure switch and a very long extension cord. The noise is not as loud as it was, but I can still hear the noise most of time when the compressor starts.
It seems to me that you are hooked on air bearing arm now.👍
Btw, do you have any solution to eliminate pop noise for Silentaire compressor? I am using two solid state relays at the air pressure switch and a very long extension cord. The noise is not as loud as it was, but I can still hear the noise most of time when the compressor starts.
Don't really sure, will let you know when I get mine and determine that I do/do not have a problem. In general my system is pretty immune to anything other than a transmitting cell phone in close proximity. (It has to be since there is a 50kW AM transmitter a mile down the street from me)
I'm not exactly sure what you are doing with the solid state relays, please explain.
One thing you can try is large ferrites on the compressor power cord pretty close to the pressure switch, this should help both radiated and conducted HF harmonics during switch closure. The other thing you can do is get some snubbers (RC network designed specifically for this purpose) and install them across the switch contacts.)