Agreed, but that does not address the issue of how the NOT operator worked when he did use it. Are there undocumented restrictions on the use of NOT (i.e. not with a single variable as a conditional expression) or is the operator buggy?
I don't think it is either a bug problem nor a documentation problem.· It is more of an understanding problem, at least on my part.· The NOT operator can be used in two ways; as a boolean operation or a binary (bitwise) operation.· When using it as a binary math operator....something like ....num1 = NOT num2... then all bits are switched from their current state.· When used as a boolean operator it changes the state of the evaluated expression ...say....NOT (muted=Yes)...· (Muted = Yes) having a boolean state of·TRUE·where the NOT,·implemented as a boolean operation, changes the boolean state to FALSE.· PBASIC just didn't which I meant...it should have read my mind!
I don't believe I have ever used a language that did not have a VARTYPE boolean in which the NOT operator would do a true boolean operation not on a TYPEd number.· Basically everything works as it should (except my rusty ole brain).·····
As for logic coding, the majority of the code was written before I coded the mute circuit so it made more sense (to me) from a high level language approach to say when it is not muted then do all this stuff otherwise do that stuff.· If one replaces that variable with an expression the logical valuation of the expression·works fine whether one says when muted do this else do that or when not muted do that else do this.
oh BTW, do you remember the old FORTRAN 66 IF statement that went something like If (expression) GOTO1, GOTO2, GOTO3 ?? As I recall you could branch on positive, zero, or negative results. I was a baby when that language came out but had to recast a large Pulp and Paper plant simulator into, I think it was, PASCAL. That finally became the Advanced Simulator for the Pulp and Paper Industry (ASPPI). My prof got most of the credit and I did most of the work!! [noparse];)[/noparse]
chemania said...
Here are a couple images as requested! [noparse];)[/noparse]
Chemania
Thanks for posting the pics (I requested)...
One question I do have is, are you getting any crosstalk or noise in the audio lines from all the wires on the solder-ring board?· In the past when I build my pre-amps I still used sheilded wire to connect to the rear-panel jacks and between boards because my scope showed some crosstalk.
I only used relays (2) on my Tape Monitor circuit, so I was wondering about how much noise all those relays will pickup and mix into your audio signal.
Things to consider...Didn't know if you had a scope or not.
I don't have a scope handy. I have a buddy who does. I intend to take the board to his place before it actually gets cast into it's final form. In all probability I will probably have to go with shielded leads. As far as the "sound" goes...it beats the heck out of an Alps Black Beauty pot! BTW, this thing is on the output side of the preamp so cross talk is not as big a consideration I suppose. It is only a 10k attenuator. By putting the control on the outputs you not only attenuate the signal but the noise floor also. That makes it really nice and quiet.
·· I have to admit...Build your own Pre-Amp/Amplifier is an ambitious project.· But building it like you're doing, that's really ambitious.· I hope it works out the way you planned.· I always liked building my own Amplifiers & Pre-Amps, but I used to hate running into noise issues, not just on the audio lines, but in the power supply.
·· Once I finished a prototype that worked great on the bench.· Problem is, the cooling fan was never actually connected on the bench because it was outside the enclosure and stayed cool.· I had an LED connected to show the fan getting power.· Later when I put it all together, I found that the fan, when running, would cause a hum on the audio output.· Very annoying!
·· And once I had an issue with ripple on the power supply I built.· It used a multiple winding secondary transformer that had a common CT.· So the ripple seemed to affect the other supplies as well (Logic).· It would certainly be a good idea to get access to a scope to check these things out.· Especially with everything connected and running.
·· Good luck on it though, can't wait to see more sub-system pics posted.· This is making me want to start a new one myself!
I know where you are coming from Chris.· I would love to get into a discussion about equipment design.· Would they kick us out of the forum???· This is my third pre and my 8th amp, but it is the first time I have done uP controls.· I guess a DAC is next!· As far as the fan goes...I have already tried that one.· I have hooked up the actual fan and PS I will be using...tried variations of placement, etc.· I usually try everything conceivable and then still end up with noise (cable rerouting, equal ground lengths, and star grounding usually solves it)!!!· hehe· This pre runs at +-60vdc and is regulated and has a CRC....if that is still noisy I will add a CLC stage.· I have been wanting a scope for some time and just have not broken down and bought one.· Maybe the parallax one would be useable?
Thank you for reminding me, our topic has strayed a little off-topic.· If you would like to discuss amplifier design, etc. post a message in the "Sandbox" and I will reply there.· I'm not helping by keeping this discussion going in the BASIC Stamps forum, and for that I apologize to those reading and wondering what we're doing!
Comments
Agreed, but that does not address the issue of how the NOT operator worked when he did use it. Are there undocumented restrictions on the use of NOT (i.e. not with a single variable as a conditional expression) or is the operator buggy?
Jim
I don't think it is either a bug problem nor a documentation problem.· It is more of an understanding problem, at least on my part.· The NOT operator can be used in two ways; as a boolean operation or a binary (bitwise) operation.· When using it as a binary math operator....something like ....num1 = NOT num2... then all bits are switched from their current state.· When used as a boolean operator it changes the state of the evaluated expression ...say....NOT (muted=Yes)...· (Muted = Yes) having a boolean state of·TRUE·where the NOT,·implemented as a boolean operation, changes the boolean state to FALSE.· PBASIC just didn't which I meant...it should have read my mind!
I don't believe I have ever used a language that did not have a VARTYPE boolean in which the NOT operator would do a true boolean operation not on a TYPEd number.· Basically everything works as it should (except my rusty ole brain).···
As for logic coding, the majority of the code was written before I coded the mute circuit so it made more sense (to me) from a high level language approach to say when it is not muted then do all this stuff otherwise do that stuff.· If one replaces that variable with an expression the logical valuation of the expression·works fine whether one says when muted do this else do that or when not muted do that else do this.
Chemania
Chemania
One question I do have is, are you getting any crosstalk or noise in the audio lines from all the wires on the solder-ring board?· In the past when I build my pre-amps I still used sheilded wire to connect to the rear-panel jacks and between boards because my scope showed some crosstalk.
I only used relays (2) on my Tape Monitor circuit, so I was wondering about how much noise all those relays will pickup and mix into your audio signal.
Things to consider...Didn't know if you had a scope or not.
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--==<{Chris}>==--
chemania (but u can call me Jeff)
·· I have to admit...Build your own Pre-Amp/Amplifier is an ambitious project.· But building it like you're doing, that's really ambitious.· I hope it works out the way you planned.· I always liked building my own Amplifiers & Pre-Amps, but I used to hate running into noise issues, not just on the audio lines, but in the power supply.
·· Once I finished a prototype that worked great on the bench.· Problem is, the cooling fan was never actually connected on the bench because it was outside the enclosure and stayed cool.· I had an LED connected to show the fan getting power.· Later when I put it all together, I found that the fan, when running, would cause a hum on the audio output.· Very annoying!
·· And once I had an issue with ripple on the power supply I built.· It used a multiple winding secondary transformer that had a common CT.· So the ripple seemed to affect the other supplies as well (Logic).· It would certainly be a good idea to get access to a scope to check these things out.· Especially with everything connected and running.
·· Good luck on it though, can't wait to see more sub-system pics posted.· This is making me want to start a new one myself!
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--==<{Chris}>==--
Jeff
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--==<{Chris}>==--