| no ts. [message #1897] |
Thu, 22 May 2008 17:43  |
 slikviq
Messages: 36
Registered: May 2008
|
Member |
|
|
|
i finally got the atoner working but the tone sweep is not working. ive checked all the connections and ive made sure the switch is wired just like the diagram, is that wrong? is there a reason for the empty transistor slot 2n3904? the only other thing i could think of is the ic says 14558 but the instructions say 4558, any suggestions? what happens is that the tone sweep doesnt make any noise with any of its four knobs,except for the speed knob which makes a tone when turned all the way up, and it makes this noise in bypass mode as well. thanks for the help.
[Updated on: Thu, 22 May 2008 17:44]
|
|
|
|
|
|
|
|
|
|
|
| Re: no ts. [message #1917] |
Tue, 27 May 2008 14:55  |
dann
Messages: 829
Registered: December 2002
Location: Austin TX |
Senior Member |
|
|
Hey... thanks for your patience over the holiday weekend, I'm realizing I need to write the definitive tweaking guide to the Sweptoner.
Let's start with this....
Dial in this setting:
-TS volume all the way up
-Blend all the way down
-Squelch all the way down (you should already have tweaked the squelch trim pot)
-Position all the way up (you should already have tweaked the position trim pots)
-LFO Depth all the way down
-Envelope Depth all the way down
-TS Depth down, but not clicked off
-TS Speed at the slowest speed (all the way down)
Now turn the TS Pitch knob from all the way down to all the way up. You should hear a steady tone sweep from very low to very high. If the tone doesn't come in until TS Pitch is already 25%-50% up, that's probably a FET tweaking issue, but the effect is working.
Now turn TS Pitch to a nice middle-range pitch. Slowly turn TS Speed up. The TS LED should start flashing faster and faster. At maximum, you should hear a low tone (the TS LFO is oscillating in the audio range). Turn it back a bit to a setting where the LED flashes about 2-4 times per second.
Now gradually turn the TS Depth knob up. At first you'll continue hearing a steady tone, but then the tone will start to modulate up and down in pitch, in time with the flashing TS LED. At the maximum the pitch should go several octaves from a low tone to whatever the TS Pitch knob is set at.
After everything works more or less, Tonesweep Atoners sometimes need a simple resistor change to maximize the TS Depth modulation. The fix is to replace the 2k7 resistor that's between the TS_DEPTH connectors and the 2N5485 FET, with a 220k. (I've had to do this in more or less half the Sweptoners, but they seem to need it in waves, probably due to differences in production batches of the 2N5485 FETs)
The next thing, sometimes done in conjunction with the 2k7/220k resistor change, is that Sweptoners sometimes need their FETs to be selected. This is done by trying FET after FET until a good sounding one is found. "Good sounding" is subjective, but characteristics to look for are wide range of pitch modulation with TS Depth at max, and good pitch range for TS Pitch knob, and a nice sounding timbre to the TS tone.
After a good FET is found, sometimes the pitch range needs to be set in case the lower end of the TS Pitch pot produces no sound. This can be done quickly by putting a resistor in parallel with the 100k TS Pitch pot. For instance if the pitch becomes audible at 50%, then that equates to a pot value of 50k, so we need to put a 100k resistor in parallel (100k parallel to 100k equals 50k)
Finally, the TS Speed can be tweaked if desired. Perhaps you want to use slowly rising and falling pitch sounds. Perhaps you want only very rapid sounds. Perhaps you want to use the audio-range FM modulation LFO sound and don't care for slowly modulating sounds.... You can set the range by changing the 10uF cap next to the 4558 in the TS section. A 100uF will make it super slow, and a 1uF will make it super fast... You also can set a limit on the fast end of the range by changing the 100 ohm resistor that's connected to TS Speed lug 2. A larger value will limit the fast range more. If you don't limit the range at all, it will stop oscillating when you turn speed all the way up, so it should have some resistance there.
Hope that helps!! I know that's a lot of info, but it's how I've done it for years. If anyone doesn't have spare parts laying around and wants to tweak it, email me and I will mail you a free baggie of misc resistors and caps and some FETS (you pay for postage outside the USA).
|
|
|
|
|
|
|
|
|
|
|
| Re: no ts. [message #1945] |
Wed, 09 July 2008 10:08 |
dann
Messages: 829
Registered: December 2002
Location: Austin TX |
Senior Member |
|
|
TS Depth is OK, it sounds like it's working, but the only thing to do about it going to full when on is to try a bunch of different FETs. But I wouldn't worry about it
TS Pitch is the one I'm not sure is working. Can you get different tones, or just that one high pitch?
[Updated on: Wed, 09 July 2008 10:08]
|
|
|
|
| Re: no ts. [message #1949] |
Sat, 12 July 2008 15:31 |
dann
Messages: 829
Registered: December 2002
Location: Austin TX |
Senior Member |
|
|
Ok, I see that you are turning the pitch knob and the tone is sorta changing, but it should go from a low pitch to a high pitch (it's just staying at a high pitch and cutting out).
Check around the TS Pitch pot, and the 555 chip. Is the 0.1uf (104) cap from pin 2/6 of the 555 OK? Does the TS Pitch pot connect to pins 6 and 7 of the 555? Are pins 2 and 6 connected? Use a meter, not just your eyes to verify connections.
Is the TS Pitch pot 100k?
[Updated on: Sat, 12 July 2008 15:37]
|
|
|
|
|
| Re: no ts. [message #1960] |
Thu, 31 July 2008 05:23 |
slikviq
Messages: 36
Registered: May 2008
|
Member |
|
|
the pot is 100k, how to i check the 555 with the voltage meter?
could this be due to the 2n3904 being from radio shack?
[Updated on: Thu, 31 July 2008 05:25]
|
|
|
|
|
| Re: no ts. [message #2149] |
Thu, 12 March 2009 06:22 |
slikviq
Messages: 36
Registered: May 2008
|
Member |
|
|
|
i never did get this to work...how much would it cost for me to send this in and have you guys get it working?
|
|
|
Members
Search
FUDforum help
Register
Login
Home
E-mail to friend 
