Alembic Guitars Club
Alembic products => Owning an Alembic => Troubleshooting => Topic started by: djmay on July 14, 2022, 06:17:01 AM
-
I have had the SF2 unused for 17 years (long story). I set it in mono mode, plugged into front jack, Filter A sounds wonderful and nothing out of Filter B. I set stereo mode and checked both filters independently, plugging into rear jacks. Both filters work. Any ideas?
Second question; can the two filters be used in series, in stereo mode. Take output of Filter A into input of Filter B?
Thank you for any assistance.
-
Hi there djmay welcome to the club.
Here is a link to the SF-2 pdf manual so you can check the connection options.
http://alembic.com/support/SF2_Manual.pdf (http://alembic.com/support/SF2_Manual.pdf)
-
Thank you. I already have the manual. The problem is that Filter B is not functioning in mono mode and I cannot figure out why.
-
Maybe it has to do with having to clean all pots and jacks. If it was sitting unused for years you may have some corrosion/oxidation built up. Turn all control knobs fully both directions fifty times at least. Then take a 1/4” cable and plug it in and out of each jack fifty times each to try to clean them out. If the signal travels through connected pots and jacks whether plugged into them or not it can get interrupted by corrosion/oxidation, from what I understand. Worth a try.
It may also have to do with the way you have it wired. Are you going in and out of a preamp effects send and return? If so, check the manual wiring diagrams again to make sure you have it right.
-
I have had the SF2 unused for 17 years (long story). I set it in mono mode, plugged into front jack, Filter A sounds wonderful and nothing out of Filter B. I set stereo mode and checked both filters independently, plugging into rear jacks. Both filters work. Any ideas?
Second question; can the two filters be used in series, in stereo mode. Take output of Filter A into input of Filter B?
Thank you for any assistance.
Regarding the second question; I seem to remember that there is a way to jumper and do this on the back of the unit. Should be in the manual you have. My SF-2 is in the effects loop of my F-1X, so your scenario may be different.
-
Here is a screen grab from the manual that shows the connection option utilizing a jumper cable between the output of channel A and channel B. I have never tried this and been curious as to what sonic advantage this would have over running in mono by plugging into channel A and out of B for the return.
-
+1 for cleaning the jacks, especially the "B IN" jack. It comes into play with respect to stereo/mono switching.
Regards,
-nate.
-
Maybe it has to do with having to clean all pots and jacks. If it was sitting unused for years you may have some corrosion/oxidation built up. Turn all control knobs fully both directions fifty times at least. Then take a 1/4” cable and plug it in and out of each jack fifty times each to try to clean them out. If the signal travels through connected pots and jacks whether plugged into them or not it can get interrupted by corrosion/oxidation, from what I understand. Worth a try.
It may also have to do with the way you have it wired. Are you going in and out of a preamp effects send and return? If so, check the manual wiring diagrams again to make sure you have it right.
Thank you. I will try that in a few days. I brought the SF2 back to Switzerland and have to buy a power supply for here.
-
Here is a screen grab from the manual that shows the connection option utilizing a jumper cable between the output of channel A and channel B. I have never tried this and been curious as to what sonic advantage this would have over running in mono by plugging into channel A and out of B for the return.
Thank you
-
+1 for cleaning the jacks, especially the "B IN" jack. It comes into play with respect to stereo/mono switching.
Regards,
-nate.
Thank you
-
Thank you. I will try that in a few days. I brought the SF2 back to Switzerland and have to buy a power supply for here.
Make sure you get the right power supply. If the polarity is wrong it will fry the choke in the SF-2 and it will need to be repaired. If you haven't seen it here is a link to the FAQ about the power supply.
https://club.alembic.com/index.php?topic=264.0
Where do you live in Switzerland? I went to college there at the now defunct Albert Schweitzer College which was in Churwalden (20 minutes or so up the pass outside Chur). I loved Switzerland but sadly have never had a chance to go back. I am pretty amazed that recent pictures I have seen of Churwalden show very little change in the area over the last 50 years.
-
I believe that unit has internal switching on the jacks that will look like a set of points on an older car. You might need to open it up and clean the points by using very fine sandpaper (I use 1000 grit 'wet' style sandpaper but with no water) across the points. You spread them apart slightly and insert the sandpaper and close them and then gently rub the sandpaper around, then you pull it out.
-
Thank you. I will try that in a few days. I brought the SF2 back to Switzerland and have to buy a power supply for here.
Make sure you get the right power supply. If the polarity is wrong it will fry the choke in the SF-2 and it will need to be repaired. If you haven't seen it here is a link to the FAQ about the power supply.
https://club.alembic.com/index.php?topic=264.0
Where do you live in Switzerland? I went to college there at the now defunct Albert Schweitzer College which was in Churwalden (20 minutes or so up the pass outside Chur). I loved Switzerland but sadly have never had a chance to go back. I am pretty amazed that recent pictures I have seen of Churwalden show very little change in the area over the last 50 years.
I live in Horgen, Kanton Zurich.
-
I believe that unit has internal switching on the jacks that will look like a set of points on an older car. You might need to open it up and clean the points by using very fine sandpaper (I use 1000 grit 'wet' style sandpaper but with no water) across the points. You spread them apart slightly and insert the sandpaper and close them and then gently rub the sandpaper around, then you pull it out.
Thank you. I was also considering spraying contact cleaner on jacks and switches.
-
Contact cleaner is okay (such as DeOxit 5) but rather than spray directly, put a small amount on a pipe cleaner, or even on a 1/4" plug. Just don't do what one Wire Dunce did (points sheepishly at self) and hose one out with that handy little straw they give you. ::)
-
Where do you live in Switzerland? I went to college there at the now defunct Albert Schweitzer College which was in Churwalden (20 minutes or so up the pass outside Chur). I loved Switzerland but sadly have never had a chance to go back. I am pretty amazed that recent pictures I have seen of Churwalden show very little change in the area over the last 50 years.
I live in Horgen, Kanton Zurich.
[/quote
Spent a week in Zurich and remember it as a nice city. Favorite local site for me was the church with the Marc Chagall stained glass windows. The group I was with also stayed in Cartigny outside of Geneva for about a month. I liked Zurich a lot more than Geneva. But since I am not much of a city person nothing beat being in Churwalden up in the mountains. My wife and I are hoping we can travel to Europe at some point. She lived and taught English in the Czech Republic and then Spain. We both would love to show each other the areas where we lived.
Good luck sorting out your SF-2. If you try the parallel connection in mono let us know your impressions.
-
I am pleased to report that both filters in the SF2 are functioning. I have it operating with the preamp and mono parallel.
I inserted a plug in each jack about 50 times and activated the mono switch about 50 times to clean the contacts.
Thank you all for the suggestions.
-
Glad you got it working. The SF-2 is a great tone shaper.
Bill, tgo
-
Where do you live in Switzerland? I went to college there at the now defunct Albert Schweitzer College which was in Churwalden (20 minutes or so up the pass outside Chur). I loved Switzerland but sadly have never had a chance to go back. I am pretty amazed that recent pictures I have seen of Churwalden show very little change in the area over the last 50 years.
I live in Horgen, Kanton Zurich.
[/quote
Spent a week in Zurich and remember it as a nice city. Favorite local site for me was the church with the Marc Chagall stained glass windows. The group I was with also stayed in Cartigny outside of Geneva for about a month. I liked Zurich a lot more than Geneva. But since I am not much of a city person nothing beat being in Churwalden up in the mountains. My wife and I are hoping we can travel to Europe at some point. She lived and taught English in the Czech Republic and then Spain. We both would love to show each other the areas where we lived.
Good luck sorting out your SF-2. If you try the parallel connection in mono let us know your impressions.
If you ever return to Switzerland, let me know.
I have SF2 set in mono and using the parallel setup. Filter A is highpass, about 80 frequency, Damping 6 on my 5-string fretless and 10 on my 6-string fretted. Filter B is lowpass, about 1200 frequency, Damping 10 on both basses. On both basses (active), I have cut bass and treble 100%. This is my only tone control at the moment, except for tone controls on the amp.
-
Good news that all your SF-2 needed was a good cleaning. Always amazed at how many problems can be solved by simple means and thanks for reporting back about the mono parallel mode. There are so many ways to configure an SF-2.
Will definitely get in touch if we make it to Switzerland. At this point we have been reluctant to get on a plane flight longer than an hour and a half due to the pandemic.
-
Stephen
If you do decide to travel you’ll have no problems if on European or Asian airlines and in airports in those geographic areas as everyone is still masked. U.S. airlines and airports on the other hand are a different story. I just returned form a three week work related trip to the Czech Republic, Korea, Japan and Vietnam. At airports and on airlines in those countries as well as Istanbul, where we had a transit stop, everyone was masked and careful not to socially interact too close to each other. Returning through LAX yesterday, however, my quick survey showed 1 in 20 people using masks despite ongoing audio warnings to stay masked and signs all over the place.
-
Thanks for the “boots on the ground” airport info Brian. Sounds like you covered a lot of territory in a short amount of time. We have remained vigilant about masking indoors, no guarantees of course, but always surprised to see a lack of simple precautions by the majority of those around us.
“Think positive, test negative” - Jorma Kaukonen