Maybe what they really should make next?

[eric coleridge]

My "bunch of components inside a wooden case" statement was also adressed at people with the knowledge (and the ear - thanks MC ) to redesign synth circuits to not feel intimidated by the Mini´s humongous reputation as the best sounding analog synth ever.

Eric, from your posts to the Moog sound addiction thread I thought you were building a modular "from scratch".
If you want my advice, selecting components is really no big deal and you can always ask here for help. There are schematics and kits around to make you more familiar with electronics that may be very rewarding.

I am building my modular from scrach--for the most part. I've used a few MFOS PCBs--but lately I've just been perf boarding schemos that I find on the internet... I have a huge bookmark library of schemo sites if anyones interested...
Indeed, I've learned most everything I know about electronics--certainly not enough to brag about-- from the internet... and have recieved much help here too, thanks...

Did you know about this? Altough it´s for novices, there are great sounding projects following the 1V per Octave rule. it´s a great source of information.
http://www.musicfromouterspace.com/anal ... age=ANALOG
Click on the Soundlab Mini-Synth page. Listen to the sound samples. Have fun.

Yeah, I've built a couple of their modules.

These MFOS circuits-- and the others I've built --do not, however, call for specially selected components... so, I think we are misunderstanding one another again (although the first time it was just a joke ).

[Mooger5]

Do you mean matching pairs or quads? There is a simple circuit for matching transistors in the minimoog service manual. It´s a tedious task from what I´ve read.
You know, usually devices from the same batch have the same batch number next to the part number, so it´s better to ask for components in the same tray or rail than picking them up from a "junk" box if you know what I mean.
The only matched components I needed so far were output valves to even stereo channels. I purchased them already matched. Maybe there are some one selling already matched transistors too.

Then of course there´s the integrated solution...

[eric coleridge]

Do you mean matching pairs or quads? There is a simple circuit for matching transistors in the minimoog service manual. It´s a tedious task from what I´ve read.

This is not the only situtation where components need to be specially selected. I am not an expert, as you may be, but I have been unable to complete otherwise "simple" circuits because I did not have the access or ability to hand select required components.

Which is one reason (I would guess their are other reasons also) that I disagreed with your statement that the average DIYer would be able to just assemble any vintage synthesizer such as the MiniMoog-- even if provided with the PCB.

It's of little consequence to me, because there are numerous circuits designed for average DIYers (and perhaps below average, like me) that I'm fully satisfied with. The MFOS circuits I've built are fantastic, and I've had good results elsewhere as well(Digisound, Ken Stone, etc).

[Mooger5]

I am not an expert, as you may be

I am definitely not an expert. I still lack some basic knowledge as I´ve already posted somewhere. Audio electronics are fascinating and immensely gratifying when everything goes right or gets fixed. If you see me giving advice related to mods of debugging it´s not to show-off how cool I am, far from that. I just like to share information much as I like to learn and I still need to learn a lot.

I have been unable to complete otherwise "simple" circuits because I did not have the access or ability to hand select required components.

Sorry, but I´m still not getting what you mean. Does it have to do with reading resistor colour codes or something? Please provide an example.

It's of little consequence to me, because there are numerous circuits designed for average DIYers (and perhaps below average, like me) that I'm fully satisfied with. The MFOS circuits I've built are fantastic, and I've had good results elsewhere as well(Digisound, Ken Stone, etc).

Well, I think you officially belong to the average DIYer group Below average I respectfully call the guy who installs himself his new car stereo speakers or builds an electronic doorbell kit with "solder sculptures" and forgets about it. Above average I consider everyone who build stuff with such attention to detail and cosmetics you´d take their creations for something that came right out of a factory. Often people like their work so much that eventually a hobby turns into a successful business.
I think Bob Moog had been an above average DIYer before he started selling theremins.

To conclude, if you´re able to populate MFOS boards and all I don´t see why you couldn´t build a Minimoog if PCBs were available, at least something like a MidiMini ( or MidiMoog as it was known here), a rack mounted Mini built with genuine parts by Studio Electronics.

[eric coleridge]

If you see me giving advice related to mods of debugging it´s not to show-off how cool I am, far from that. I just like to share information much as I like to learn and I still need to learn a lot.

Sorry, I just didn't want to presume to tell you something you probably already knew about. I had the impression that you might be a professional. But I don't always read whole entries... just skim...
I think it's great to share info too..

Sorry, but I´m still not getting what you mean. Does it have to do with reading resistor colour codes or something? Please provide an example.

Yeah, exactly, I'm talking about resistor color codes. I had assumed those stripes were just for decoration, but now I understand it's what the parts list is referring to when it says 'special selected'. Thanks

To conclude, if you´re able to populate MFOS boards and all I don´t see why you couldn´t build a Minimoog if PCBs were available, at least something like a MidiMini ( or MidiMoog as it was known here), a rack mounted Mini built with genuine parts by Studio Electronics.

I guess you're right. Maybe I'll try to build a perfboard 2600 too.

[Mooger5]

Here http://www.dannyg.com/examples/res2/resistor.htm . Add it to your favourites and you´ll soon memorize it.

Edit: Note that it just shows three bands plus gold and silver bands for tolerances of 5 and 10%. For 1 and 2% tolerances there are also the four band resistors with the fourth band following the same logic as the others. That is brown for 1% and red for 2% tolerance.

[eric coleridge]

Mooger 5, you remind me of Data from Star Trek: Next Generation. He's a very smart android who longs to have a human heart so that he can understand complex human phenomena like humour.

[Mooger5]

Hmm... so you were being ironic... hmm... no wonder why I enjoy listening to Kraftwerk so much... hmm... interesting!

Edit:

[Kevin Lightner]

I had assumed those stripes were just for decoration, but now I understand it's what the parts list is referring to when it says 'special selected'.

The stripes denote the value and tolerance, but "special selected" is another thing entirely.

This is where a resistor value is chosen specifically by hand, often where a trimmer could have been installed instead.

"Hand matched" (also called selected) is where multiple resistors of the same value are matched very closely to each other.

For example, the octave range setting on a Minimoog has matched resistors. The actual value is not as important as them being all exactly the same.

[eric coleridge]

I had assumed those stripes were just for decoration, but now I understand it's what the parts list is referring to when it says 'special selected'.

The stripes denote the value and tolerance, but "special selected" is another thing entirely.

Thanks Kevin... but I was just joking...apparently my humour is evading everyone's sensibilities... maybe I'm the one who is most like Data from ST: Next Gen.

These aren't the only examples of specially selected components, though, right? Aren't there many applications where a part should ideally be selected for special characteristics (beyond selecting matched pairs)?
I was trying to put together a cicuit from the MS20, the pitch to voltage circuit, but I noticed that the parts list was calling for all special selected transistors-- but there wasn't the normal box around them on the schematic which I know to mean matched pairs... so I was thinking that they were selected for some other characteristic.

This isn't the only place I've encountered this either... so I was saying, that this issue might stand in the way of an average DIYer assembling a MiniMoog, or other precision claibrated circuits...

[Kevin Lightner]

Yes, there's all sorts of components selected at the time of manufacturing.
Opamps for offset, transistors for gain, etc.
Noise diodes are almost always done by hand/ear.

Some parts may have been preselected for certain tasks and put into general stock at a manufacturer also.
In other words, a schemo and parts list may only show X opamp by its common number, but may have been a preselected part regardless.

Then there's also manufacturer and period specific parts.
For example, in a Polymoog they used Motorola 4046 chips.
I've never found another make of this same IC that worked correctly in PMs.

Some Polyfusions and other make synths want only cmos A series chips in certain places. Newer versions won't work.

[eric coleridge]

Thanks.

And this is probably not the only issue standing in the way of a DIYer who wants to "assemble" a MiniMoog or other classic vintage synth... right?

If it was just a matter of assembling a schenmatic and parts list, there would be a million people building MiniMoogs and 2600s...But, of course, it's not that simple.

This is what I was trying to get accross... but wasn't sure exactly why...

[Mooger5]

I was trying to put together a cicuit from the MS20, the pitch to voltage circuit, but I noticed that the parts list was calling for all special selected transistors-- but there wasn't the normal box around them on the schematic which I know to mean matched pairs... so I was thinking that they were selected for some other characteristic.

You can build that P2V.

Read the parts list again: the (special selected) mention is only for the 2SC-945 part number written above it , it´s not a sub-title for the next 16 transistors .

Look at the circuit diagram nr.1: the single transistor is in the output stage right after the LPF section. Notice the " 945 selected" mention.

[Kevin Lightner]

The MS-20 P/V schematic I have only has 2 transistors, neither C945's, nor selected.

Hmmm?

[Mooger5]

The transistors in the P2V are general purpose 2SC-1685, included in the 16 parts Eric thought needed to be special selected. But he misread the parts list. The only special part is the 2SC-945 in the output section of the synth section. The P2V is independent of that section. That´s why Eric can build it without worrying.

http://www.korganalogue.net/korgms/imag ... /parts.gif

Look at the parts list, and then look at Circuit Schematic (1).