| Author |
Message |
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
 Posted: Wed Apr 16, 2008 2:19 pm Post subject:
Re: Tau Pipe Phaser re-run PCBs |
  |
|
| Stavros wrote: |
Is this also applicable to the Solina-Triple Chorus output connections?
|
No - the Triple Chorus outputs are all AC coupled already.
There, with a single supply voltage, AC coupling is an absolute must, und therefore part of the PCB. (And, OTOH, the single supply also allows ordinary, polarized electrolytic caps everywhere.)
| Quote: | 2. I have problem in finding a Tempco resistor. I have looked at Reichelt/Banzai/Das Musikding, but have not seen any code for Tempco resistors. I may have missed it. I will appreciate some supplier suggestion and/or an order code number for a 1k one.
|
IMO, you don't really need a tempco resistor for anything except VCOs, or filters that can be used as VCOs. Who cares for a little variation of keyboard tracking on a phaser, of all things ?!
Well, there seems to be some demand, and it's easy to design the circuit in a way that you can use a tempco resistor where otherwise there would be a resistor (divider) anyway - so I did.
I think Farnell has them, but I never bought them cause I got mine from a friend. And last time I checked Synthesis Technology also sold some, though these are bigger / better ones that those I remember seeing at Farnell.
JH.
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
 |
loopcycle
Joined: Nov 06, 2006
Posts: 101
Location: California
|
| Posted: Mon Apr 21, 2008 8:34 pm Post subject:
|
|
|
im finally building my tau.
what are the correct values for the 1V/O and osc level (mod depth) pots?
thanks! |
|
|
Back to top
|
|
|
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
| Posted: Mon Apr 21, 2008 11:14 pm Post subject:
|
|
|
| loopcycle wrote: | im finally building my tau.
what are the correct values for the 1V/O and osc level (mod depth) pots?
thanks! |
1V/Oct input doesn't need a pot. You set the 1V/Oct scale with the trimpot on board.
If you *want* a manual fine tuning of the tracking, put a small value pot (like 1k or 500R) in *series* with this input (as a variable resistor; not as a variable voltage divider!), put it into 12 o'clock position, and *then* adjust the on-board trimpot for 1V/Oct. Then you can change the scale with the front panel pot slightly higher or lower. (I normally use tiny bourns pots with 3.18 mm shaft for this.)
See http://www.jhaible.heim.at/tau/jh_tau_signal_and_cv_connections.pdf .
Osc Level pot value should be documented on my Tau page, too:
http://www.jhaible.heim.at/tau/jh_tau_sch_page5_pots.pdf clearly says "10k log". 
JH.
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
|
loopcycle
Joined: Nov 06, 2006
Posts: 101
Location: California
|
| Posted: Mon Apr 21, 2008 11:46 pm Post subject:
|
|
|
| nice! thank you. i had only been looking at your hand drawn diagrams for inputs/outputs. i had not seen this page from the jh tau main page. |
|
|
Back to top
|
|
|
Stavros
Joined: Oct 30, 2007
Posts: 36
Location: Athens-Greece
|
| Posted: Tue Apr 22, 2008 1:20 pm Post subject:
|
|
|
Hi Jurgen,
I have read most of the messages that have been exchanged on the previous issue of the “TAU” phaser PCB, which have been very helpful to me.
I have still few questions/clarifications to ask you and I apologize, if I have not understood correctly something on the previous messages or should you have already given a reply that I missed.
1. I have read in one of your answers that on your module you have a switch for Slew on/off. What legend have you used for this one and where is it connected on the PCB?
2. On your New Panel which you have published, you are selecting with a switch between the 1V/Oct. CV in and the variable CV in, thus you practically have a single input (either/or). Correct? Is this switched or not (the two previous inputs I believe were not the same)
3. Signal input: On the Minimal and Deluxe version diagrams it is shown as a Switched (?) input, (connected to ground when nothing in) on the Basic version diagram it is shown as Normal input (I think). How critical is this connection to ground when no input exists?
The reason this is of special interest to me is that my modular connections are “banana” based and I am not sure how to easily make the connection when a switched input is necessary (this is also relevant to the switched “CV In” connection mentioned above). Please help!
4. Stereo input: On your New Panel you have two signal inputs with a single rotary control. Is this a Stereo (2x10k log) one and then you bridge the two signals into one path; or you bridge them before and you use a normal 10k log pot.? Or you have done something else?
5. “Remote”: Legend on your New Panel stands for CV Out. Correct?
6. Phaser Link: Connecting “Remote (CV out) with CV In of next phaser? Correct?
Could that also be valid connecting L/R Out signal to L/R Input signal of next phaser?
7. CV trim: Legend on your New Panel, is the 1k (lin?) fine tuning pot for the 1V/Oct. CV?
By the way, on “Bill and Will’s notes” on the fine tuning pot it is noted, if I recall it correctly, as 1M pot. Is this a typo error or something else?
Please excuse the ignorant/stupid questions
Many thanks and Best Regards
Stavros |
|
|
Back to top
|
|
|
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
| Posted: Tue Apr 22, 2008 2:29 pm Post subject:
|
|
|
| Quote: | | I have read in one of your answers that on your module you have a switch for Slew on/off. What legend have you used for this one and where is it connected on the PCB? |
"SMOOTH"
http://www.jhaible.heim.at/tau/jh_tau_component_overlay_with_comments.pdf
| Quote: | | On your New Panel which you have published, you are selecting with a switch between the 1V/Oct. CV in and the variable CV in, thus you practically have a single input (either/or). Correct? |
Correct
| Quote: | | Signal input: On the Minimal and Deluxe version diagrams it is shown as a Switched (?) input, (connected to ground when nothing in) on the Basic version diagram it is shown as Normal input (I think). How critical is this connection to ground when no input exists? |
Not critical
| Quote: | | this is also relevant to the switched “CV In” connection mentioned above). Please help! |
Well, here you need normalizing. With bananas? A switch, maybe ...
| Quote: | | Stereo input: On your New Panel you have two signal inputs with a single rotary control. Is this a Stereo (2x10k log) one and then you bridge the two signals into one path; or you bridge them before and you use a normal 10k log pot.? Or you have done something else? |
2nd input is just for true stereo bypass. Phaser input is derived from one channel only.
| Quote: | | “Remote”: Legend on your New Panel stands for CV Out. Correct? Could that also be valid connecting L/R Out signal to L/R Input signal of next phaser? |
It's probably meant for running two in parallel, for true stereo. But what you describe may be an interesting thing to try as well!
| Quote: | | CV trim: Legend on your New Panel, is the 1k (lin?) fine tuning pot for the 1V/Oct. CV? By the way, on “Bill and Will’s notes” on the fine tuning pot it is noted, if I recall it correctly, as 1M pot. Is this a typo error or something else? |
1k is right.
JH.
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
|
Stavros
Joined: Oct 30, 2007
Posts: 36
Location: Athens-Greece
|
| Posted: Wed Apr 23, 2008 9:42 am Post subject:
|
|
|
Hello Jurgen.
in one of your answers in a previous message you write:
"The 100k resonance pot has a 20k (final value tbd) resistor in series with its cw end. (i.e., cw end of pot goes to 20k resistor, 20k resistor goes to board connector.)
The switch of the pull pot is connected to short the 20k resistor, when the knob is pulled out. So I get nice high resonance *without* oscillation with the knob pushed in, and screaming oscillation when pulled out.
You can also wire this up with an ordinary pot and switch, of course."
Q. The switch will connect the CW end of the pot to the board connector either directly or through the 20k resistor, correct?
Thanks and Best Regards
Stavros |
|
|
Back to top
|
|
|
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
| Posted: Wed Apr 23, 2008 1:12 pm Post subject:
|
|
|
| Stavros wrote: | Hello Jurgen.
in one of your answers in a previous message you write:
"The 100k resonance pot has a 20k (final value tbd) resistor in series with its cw end. (i.e., cw end of pot goes to 20k resistor, 20k resistor goes to board connector.)
The switch of the pull pot is connected to short the 20k resistor, when the knob is pulled out. So I get nice high resonance *without* oscillation with the knob pushed in, and screaming oscillation when pulled out.
You can also wire this up with an ordinary pot and switch, of course."
Q. The switch will connect the CW end of the pot to the board connector either directly or through the 20k resistor, correct?
Thanks and Best Regards
Stavros |
Correct.
I see I'll have to scan and upload the documetation of my second Tau prototype some time ...
... but not now; I still have a lot of FS-1a boards to pack and ship and print invoices ...
JH.
Now playing: Tangerine Dream Live, Sydney - February 22nd 1982
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
|
Stavros
Joined: Oct 30, 2007
Posts: 36
Location: Athens-Greece
|
| Posted: Thu Apr 24, 2008 9:12 am Post subject:
|
|
|
Hello Jurgen,
Where is the Bounce / Direct Switch, that appears on your New panel, connected on the PCB?
Best Regards
Stavros |
|
|
Back to top
|
|
|
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
| Posted: Thu Apr 24, 2008 9:23 am Post subject:
|
|
|
| Stavros wrote: | Hello Jurgen,
Where is the Bounce / Direct Switch, that appears on your New panel, connected on the PCB?
Best Regards
Stavros |
That's part of a (rather large) extra circuit I've built on a veroboard. Not part of the TAU PCB, I'm afraid.
That's what I meant above: the stuff I'll publish at some time.
JH.
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
|
funkyfarm
Joined: Jan 21, 2007
Posts: 583
Location: France
Audio files: 3
|
| Posted: Thu Apr 24, 2008 1:33 pm Post subject:
|
|
|
| Stavros wrote: | Hello Jurgen,
Where is the Bounce / Direct Switch, that appears on your New panel, connected on the PCB?
Best Regards
Stavros
|
Stavros,
that's not fair play !
I mean I was planning to wait for a week or two more before putting Jurgen in this awkward situation 
Panel is still made of cardboard ! |
|
|
Back to top
|
|
|
PrimateSynthesis
Joined: May 02, 2008
Posts: 69
Location: U.S.A.
|
Posted: Sat May 03, 2008 9:02 am Post subject:
 |
|
|
I have a number of questions. Hopefully, others will chime in as I'm sure that JH has much better things to do :)
Firstly, in order to determine what size transformer is needed and how much additional circuitry can be powered, approximately how much current does the phaser draw??
"Can use either a 18V single secondary winding, or two 18V secondary windings, or a 36V CT. In the first case, the board does half wave rectification; in the other cases, full wave rectification. If using a CT transformer, the center tap goes to pins 2 or 4 of the 5-pin connector. "
I don't understand, how can an 18V CT and 36V CT could both work well?? Also, putting more than 36V across two 35V caps seems like a bad idea.
Secondly, I'm rather confused about the stereo matrix. I would like to add wet/dry controls to each channel, in order to use it in line. At first, I thought I would use two stereo pots to mix the input with each output. Upon further review, it seems that the input and outputs are already being at U4. Is there a more elegant way to add wet/dry controls without adding additional summing amps??
Thirdly, in trying to add more modulation sources, such as an envelope follower, what is the voltage range of the internal modulation sources?? In other words, what is the level of the internal LFO, and the expected values of CV IN and CV OUT?? I'm guessing the dividers around U5B are to provide a special curve??
Finally, what is the intended goal or set-up procedure for the gain trimmer R18 and resonance trimmer R5?? Is there a problem with increasing the R5 and decreasing R4 by the approximately same amount (eg. making R5 100K and R4 160K)?? Is there any advantage in putting R4 on the panel?? There seem to be two pots that both control resonance.
Thanks :) |
|
|
Back to top
|
|
|
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
| Posted: Sat May 03, 2008 10:15 am Post subject:
|
|
|
| PrimateSynthesis wrote: | | I have a number of questions. Hopefully, others will chime in as I'm sure that JH has much better things to do |
Better things? Soldering the 2nd board of string filter, and layouting the Interplating Scanner & Hammond Vibrato board.
| Quote: | | Firstly, in order to determine what size transformer is needed and how much additional circuitry can be powered, approximately how much current does the phaser draw?? |
You'll notice that I permanently evade these questions. Why? because it depends on so many things. If I'd sell you a complete kit (which, thank God, I don't - I never want to go into that business!), I'd know what components I'm using and all.
But all the power supply stuff depends on so many factors. My suggestion is to oversize the PSU: I'm using a 7VA wallwart and never had problems. These are cheap as cheap can be, so I don't even want to find out if imy circuit still runs at 3VA, if it does so comfortably or just barely, if it still does under heavy load, and so on.
As for powering othe rmodules from the onboard PSU: It's certainly possible in some cases, but you're completely on your own with this.
Just some hints, and one example: The rectifiers and the regulators are oversized. They work up to 1A. But certainly not without heat sink. And you'd need bigger reservoir caps. The 470uF are quite oversized already, but this also depends on the AC voltage that comes from your wallwart or mains transformer. Lower AC voltage => less heat, but bigger capacitor needed, and more sensitive to brownout.
Example: I did power a second Tau board, plus the auxiliary circuit needed for a Dimension-D-like configuration, from a first Tau board, and it's fine for testing. But I'd never leave the room without switching it off, because the voltage regulators get damn hot. For a permanent solution, the PSU will have to be specially designed, with heatsink and all. I doubt there's much advantage in feeding more boards from the PSU of a single board.
| Quote: | "Can use either a 18V single secondary winding, or two 18V secondary windings, or a 36V CT. In the first case, the board does half wave rectification; in the other cases, full wave rectification. If using a CT transformer, the center tap goes to pins 2 or 4 of the 5-pin connector. "
I don't understand, how can an 18V CT and 36V CT could both work well?? Also, putting more than 36V across two 35V caps seems like a bad idea. |
Oh, two separate 18V windings are the same as a 36V CT winding.
(18V CT is not enough!)
| Quote: | Secondly, I'm rather confused about the stereo matrix. I would like to add wet/dry controls to each channel, in order to use it in line. At first, I thought I would use two stereo pots to mix the input with each output. Upon further review, it seems that the input and outputs are already being at U4. Is there a more elegant way to add wet/dry controls without adding additional summing amps??
Thirdly, in trying to add more modulation sources, such as an envelope follower, what is the voltage range of the internal modulation sources?? In other words, what is the level of the internal LFO, and the expected values of CV IN and CV OUT?? I'm guessing the dividers around U5B are to provide a special curve??
Finally, what is the intended goal or set-up procedure for the gain trimmer R18 and resonance trimmer R5?? Is there a problem with increasing the R5 and decreasing R4 by the approximately same amount (eg. making R5 100K and R4 160K)?? Is there any advantage in putting R4 on the panel?? There seem to be two pots that both control resonance.
Thanks |
I think much of this has been coverd here, in this very thread, already.
JH.
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
|
PrimateSynthesis
Joined: May 02, 2008
Posts: 69
Location: U.S.A.
|
| Posted: Sat May 03, 2008 1:14 pm Post subject:
|
|
|
| jhaible wrote: | | PrimateSynthesis wrote: | | Firstly, in order to determine what size transformer is needed and how much additional circuitry can be powered, approximately how much current does the phaser draw?? |
You'll notice that I permanently evade these questions. Why? because it depends on so many things. |
I don't need an exact figure. Just a rough estimate how much the basic phaser draws. Since I'm not using a wall-wart, it has a significant impact on the size and cost of the transformer.
| jhaible wrote: | | PrimateSynthesis wrote: | "Can use either a 18V single secondary winding, or two 18V secondary windings, or a 36V CT. In the first case, the board does half wave rectification; in the other cases, full wave rectification. If using a CT transformer, the center tap goes to pins 2 or 4 of the 5-pin connector. "
I don't understand, how can an 18V CT and 36V CT could both work well?? Also, putting more than 36V across two 35V caps seems like a bad idea. |
Oh, two separate 18V windings are the same as a 36V CT winding.
(18V CT is not enough!) |
I'll have to go back over it again. It seemed as though 18VAC was enough, albeit at half phase, with 1.4 times the current rating...
| jhaible wrote: | | PrimateSynthesis wrote: | Secondly, I'm rather confused about the stereo matrix. I would like to add wet/dry controls to each channel, in order to use it in line. At first, I thought I would use two stereo pots to mix the input with each output. Upon further review, it seems that the input and outputs are already being at U4. Is there a more elegant way to add wet/dry controls without adding additional summing amps??
Thirdly, in trying to add more modulation sources, such as an envelope follower, what is the voltage range of the internal modulation sources?? In other words, what is the level of the internal LFO, and the expected values of CV IN and CV OUT?? I'm guessing the dividers around U5B are to provide a special curve??
Finally, what is the intended goal or set-up procedure for the gain trimmer R18 and resonance trimmer R5?? Is there a problem with increasing the R5 and decreasing R4 by the approximately same amount (eg. making R5 100K and R4 160K)?? Is there any advantage in putting R4 on the panel?? There seem to be two pots that both control resonance.
Thanks |
I think much of this has been coverd here, in this very thread, already.
JH. |
Well, I read through all 17 pages of this thread, and took notes as I went along, before I asked. So hopefully, others will have a better answers. |
|
|
Back to top
|
|
|
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
| Posted: Sat May 03, 2008 2:04 pm Post subject:
|
|
|
| PrimateSynthesis wrote: | | jhaible wrote: | | PrimateSynthesis wrote: | | Firstly, in order to determine what size transformer is needed and how much additional circuitry can be powered, approximately how much current does the phaser draw?? |
You'll notice that I permanently evade these questions. Why? because it depends on so many things. |
I don't need an exact figure. Just a rough estimate how much the basic phaser draws. Since I'm not using a wall-wart, it has a significant impact on the size and cost of the transformer. |
Can someone who has built his phaser for the use in a +/-15V environment (MOTM, or other modular) do us a favor and measure the DC current draw? (I've got all my prototypes built with on-board PSU, and I hate to cut traces to measure the DC current.)
| Quote: | | jhaible wrote: | | PrimateSynthesis wrote: | "Can use either a 18V single secondary winding, or two 18V secondary windings, or a 36V CT. In the first case, the board does half wave rectification; in the other cases, full wave rectification. If using a CT transformer, the center tap goes to pins 2 or 4 of the 5-pin connector. "
I don't understand, how can an 18V CT and 36V CT could both work well?? Also, putting more than 36V across two 35V caps seems like a bad idea. |
Oh, two separate 18V windings are the same as a 36V CT winding.
(18V CT is not enough!) |
I'll have to go back over it again. It seemed as though 18VAC was enough, albeit at half phase, with 1.4 times the current rating... |
Well yes, the board runs nicely on half wave rectification, so you can also feed it from a single 18V winding. (A center tap isn't needed in that case, but won't hurt, as long as you do _not_ connect it!)
JH.
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
|
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
| Posted: Sat May 03, 2008 2:16 pm Post subject:
|
|
|
| PrimateSynthesis wrote: |
Well, I read through all 17 pages of this thread, and took notes as I went along, before I asked. So hopefully, others will have a better answers. |
Sorry for that - I've been in a hurry, read about wet-dry mix, and thought I had just recently covered this.
Well, your questions _are_ more detailed.
The CV range:
Positive only, up to about +10V.
Exact value in manual control depends on exact value of PITCH potentiometer.
Exact value in LFO depends on saturation of your specific TL072 you're using for IC6. But roughly 10V.
The manual control is a funny little circuit indeed, as it partly cancels the 1/x function of U5 and the transistor array. (The Aries version of this phaser simply connected a pot to the exponential input instead.)
JH.
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
|
PrimateSynthesis
Joined: May 02, 2008
Posts: 69
Location: U.S.A.
|
| Posted: Mon May 05, 2008 7:49 am Post subject:
|
|
|
| jhaible wrote: | Sorry for that - I've been in a hurry, read about wet-dry mix, and thought I had just recently covered this.
Well, your questions _are_ more detailed. |
No need for apologies. I know all about busy. Notice I still haven't started building this thing  That's why I tried to encouraged others to answer.
| jhaible wrote: |
The CV range:
Positive only, up to about +10V.
Exact value in manual control depends on exact value of PITCH potentiometer.
Exact value in LFO depends on saturation of your specific TL072 you're using for IC6. But roughly 10V.
|
Thanks, that is great information!!
I decided to add a switch for resonance, one setting for the stock resistor and trimpot, and another for a vactrol with a trimpot as a rheostat in series.
| jhaible wrote: | | Can someone who has built his phaser for the use in a +/-15V environment (MOTM, or other modular) do us a favor and measure the DC current draw? (I've got all my prototypes built with on-board PSU, and I hate to cut traces to measure the DC current.) |
Thanks, in the meanwhile I found a 25VA transformer (Hammond 185C36) that should fit, and inexpensive 12.5 mm 1,000uF 50V caps (although 16mm could fit depending on the size of the caps in the APF). The limiting factor seems to be the dissipation of the regulators. There isn't much room in there, but I did find a couple of heat sinks that should fit. |
|
|
Back to top
|
|
|
loopcycle
Joined: Nov 06, 2006
Posts: 101
Location: California
|
| Posted: Mon May 05, 2008 11:26 pm Post subject:
|
|
|
the tau is built. and its working great! although i must have wired the CV input wrong...when i plug a dummy jack into it, the mod depth pot setting is overridden and i get full onboard modulation until i pull the jack out. ill have to look at the schematics again.
so i made a demo. http://www.twango.com/media/consumed.sound/consumed.10026
question: i left off the "down" LED from the board. is this OK or will it have a negative impact on the circuit? thanks! |
|
|
Back to top
|
|
|
jhaible
Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24
|
| Posted: Tue May 06, 2008 12:31 am Post subject:
|
|
|
| loopcycle wrote: |
question: i left off the "down" LED from the board. is this OK or will it have a negative impact on the circuit? thanks! |
That's ok.
JH.
_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
|
|
Back to top
|
|
|
Peake
Joined: Jun 29, 2007
Posts: 1113
Location: Loss Angeles
Audio files: 3
|
| Posted: Tue May 06, 2008 11:11 am Post subject:
|
|
|
Hi, thanks again for the project.
I'll take it that any AC voltage at and above 18V will be fine to power these (power sections fully installed)? |
|
|
Back to top
|
|
|
Stavros
Joined: Oct 30, 2007
Posts: 36
Location: Athens-Greece
|
|
|
Back to top
|
|
|
PrimateSynthesis
Joined: May 02, 2008
Posts: 69
Location: U.S.A.
|
| Posted: Tue May 06, 2008 1:09 pm Post subject:
|
|
|
| Peake wrote: | | I'll take it that any AC voltage at and above 18V will be fine to power these (power sections fully installed)? |
Not any AC voltage -- connecting directly to the mains will destroy it. The resulting DC voltage is likely to be higher than the AC voltage, and has to be withing the specification of the regulator (for an LM317 that's less than 5V more than the output voltage and less than 40V) and the voltage rating of the rectifier filter caps. Also, the more you unnecessarily increase the voltage the more heat the regulators will produce.
| Stavros wrote: | | When using a single 18VAC transformer (No CT) the two phases should be connected to pins 1 and 5 of the 5 pin connnector. Is it correct? All other pins would remain free. |
Yes, that is correct.
| Stavros wrote: | | Could that be an option or is it tottaly wrong to connect one of the two phases to pin 2 or 4 and the other one in parallel to pins 1 and 5? |
Yes, that is totally wrong. If you are using a single secondary (no CT) do not connect AC to ground.
| Stavros wrote: | | PS. I have attached a JPG of the frontpanel that I designed for my Tau Phaser. The format follows my existing Modular general format. I have used dual in / outs to cope for my Banana based system, and standard 6.3mm jacks for alternative/direct connection to other systems/mixer etc. This needs still to be constructed. |
Bounce?? Is there a secret circuit I don't know about?? I promise I won't tell an established U.S. company famous for DSP hardware who isn't Lexicon
Although, if you are putting this in a modular that already has a +15/-15 supply, you can use that instead of building the power supply on the board. |
|
|
Back to top
|
|
|
Peake
Joined: Jun 29, 2007
Posts: 1113
Location: Loss Angeles
Audio files: 3
|
| Posted: Tue May 06, 2008 2:00 pm Post subject:
|
|
|
Peake: I'll take it that any AC voltage at and above 18V will be fine to power these (power sections fully installed)?
Primate Synthesis: "Not any AC voltage -- connecting directly to the mains will destroy it."
ARGH! TOO LATE! 
"The resulting DC voltage is likely to be higher than the AC voltage, and has to be withing the specification of the regulator (for an LM317 that's less than 5V more than the output voltage and less than 40V) and the voltage rating of the rectifier filter caps. Also, the more you unnecessarily increase the voltage the more heat the regulators will produce."
The local supplier has plenty of 15 and 24VAC supplies for $2.00, but zero 18VAC. Figures! Thanks. |
|
|
Back to top
|
|
|
loopcycle
Joined: Nov 06, 2006
Posts: 101
Location: California
|
| Posted: Wed May 07, 2008 8:21 am Post subject:
|
|
|
yesterday, at the primate's request  i measured the current draw on the +15v and -15v rails between the tau and the psu. i came up with the following results:
~29mA draw on -15v
~34mA draw on +15v
hope thats useful (and correct)  |
|
|
Back to top
|
|
|
Stavros
Joined: Oct 30, 2007
Posts: 36
Location: Athens-Greece
|
| Posted: Wed May 07, 2008 10:58 am Post subject:
|
|
|
Many thanks for the clarifications!
Primate Synthesis wrote: | Quote: | | Bounce?? Is there a secret circuit I don't know about?? I promise I won't tell an established U.S. company famous for DSP hardware who isn't Lexicon. |
It seems there is. JH has that switch in his own published Front Panel.
I have added this in mine as a provision in case he comes out with an add on PCB to the Tau main circuit.
The Banana and 6.3mm jacks are completly parallel (as far as signal is concerned, the 6.3 has additionally the Ground connection) with no intented simultaneous use ever. I am far for been knowledgable enough to do something more there. I suspect that it would need some additional component(s) to be able to use them simultaneously. That might be usefull on occasion but I do not know how I could do it. It might work as is.
My Modular operates with +/-12Volt DC, so I am adding a transformer and I will use the on board PSU. I am thinking of using a 16Volt AC one that I have already available, with larger than the 470uf capacitors. From my reading on PSUs, I believe even a 15Volt AC transformer of adequate Amps, and larger capacitors should be OK. Is it correct?
Best Regards and many thanks
Stavros[/quote] |
|
|
Back to top
|
|
|
|
Forum index » DIY Hardware and Software » Jürgen Haible designs
FAQ
Calendar
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
Chat Room
