Seamoon - Funk Machine  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
User avatar
modman
a d m i n
Posts: 4604
Joined: 19 Jun 2007, 17:57
Has thanked: 3460 times
Been thanked: 725 times

Post by modman »

R.G. wrote:The longer I mess with this stuff the more I realize that there is no absolute reality, no razor's edge of black and white, other than the ones we set up in our own minds. :lol:
Of course, structures with which man tries to understand reality, like laws of physics or other sciences are structures imposed on reality by the human brain. They 'are' not reazlity. Reality is shaped by he mind. :mrgreen:
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

MoreCowbell
Transistor Tuner
Posts: 1105
Joined: 06 Aug 2007, 15:39
Been thanked: 11 times
Contact:

Post by MoreCowbell »

R.G. wrote: Yeah, cool. Looks like that unit has a 33K there, if that's the position for that resistor; at least it is in that unit, perhaps or perhaps not the one I looked at long ago and far away. It's always possible the one I looked at had been tinkered with too.

So you're saying that occasionally vintage effects makers may have substituted values or lightly modified their designs as time went on ? Say it ain't so !!!

Certainly companies like Electro-Harmonix always used "absolute values" and never changed anything, so I'm sure Seamoon would never do such a thing.

[/sarcasm]

R.G.
Resistor Ronker
Posts: 339
Joined: 22 Sep 2007, 03:24
Been thanked: 38 times

Post by R.G. »

modman wrote: Of course, structures with which man tries to understand reality, like laws of physics or other sciences are structures imposed on reality by the human brain. They 'are' not reazlity. Reality is shaped by he mind. :mrgreen:
Yeah, it's like, man, like we'd have thought in the 60's - reality is in fact imaginary!~!~! :shock: :? :lol: :scratch:
So you're saying that occasionally vintage effects makers may have substituted values or lightly modified their designs as time went on ? Say it ain't so !!!Certainly companies like Electro-Harmonix always used "absolute values" and never changed anything, so I'm sure Seamoon would never do such a thing.
In my best melodramatic falsetto "Oh.... Oh! Say not so, I beg you sir!" :lol:

lynessmy
Breadboard Brother
Posts: 112
Joined: 09 Oct 2007, 02:15
Has thanked: 1 time
Been thanked: 2 times

Post by lynessmy »

lynessmy wrote:Image
Image

Resize to 25%.

10uF*** is not presented in the schematic.
1M Resistor is added for pop elimination, not sure it may help in this circuit thought. You may obsolete it if you like.

5M Pot was replaced with 1M with OPT1, OPT2 and OPT3 added for range selection with SP3T selector.
If this option is used, cut the thin trace connecting OPT1 to the POT.

If you want to build Version1, Just ignore OPT2 and OPT3...leave it blank.

Transistor used is 2N5088. No sure how it would affect the tone. NTE95 is the alternative to 40006 transistor. Be careful on the layout though.
Dual op-amp used instead 2x 741 op amp.

You will not get the vintage replica from this.
But if you like to go ahead to build and share your build report here.
I tested this with several different dual op amp (JRC4560, TL072, NE5532 and LM1458 and MC1458)...
Only the last 3 produce the funk effects. The best being lm1458.
But in any of them (the 3 that has funk sound), i loss a lots of volume there and i have to boost with a SHO.
Any suggestion?

R.G.
Resistor Ronker
Posts: 339
Joined: 22 Sep 2007, 03:24
Been thanked: 38 times

Post by R.G. »

lynessmy wrote:
lynessmy wrote: I tested this with several different dual op amp (JRC4560, TL072, NE5532 and LM1458 and MC1458)...
Only the last 3 produce the funk effects. The best being lm1458.
But in any of them (the 3 that has funk sound), i loss a lots of volume there and i have to boost with a SHO.
You're running into a common problem with really old, vintage stomp boxes - they were poorly designed by today's standards, because the designers did not have the body of knowledge we do today. At the time the Seamoon was current, having even one effect in addition to a distortion was a rich pedalboard. The fifty-pound pedalboards we take for granted simply didn't exist.

In the case of the Seamoon, there are a number of what I'd consider design defects. To start with, it's neither buffered nor true bypassed, so it has the potential to be a tone sucker. That potential is fully expressed by that 50K pot which loads down the input whether the effect is bypassed or not. Using a bipolar transistor for a variable gain element works, kind of, but it is asking for distortion on any but the most quiet notes.

One of the specific problems you've run into is the same as the problem with the almost-identical and similarly benighted ElectroHarmonix DrQ. Compare the Seamoon to this https://www.diystompboxes.com/pedals/schems/doctorq.gif. The differences are trivial. In particular, they used the same opamp, the LM1458, which has a quirk which allows it to work with its inputs nearer the negative supply than most modern opamps that are not specified as single supply or rail to rail. Jack Orman expended part of his life correcting this with the Dr Quack: http://www.muzique.com/schem/quack.gif.

The Dr Quack does the obvious: it fixes the issues with the near-ground opamp input for the envelope, and it buffers the input so there's not so much tone sucking.

lynessmy
Breadboard Brother
Posts: 112
Joined: 09 Oct 2007, 02:15
Has thanked: 1 time
Been thanked: 2 times

Post by lynessmy »

R.G. wrote:
lynessmy wrote:
lynessmy wrote: I tested this with several different dual op amp (JRC4560, TL072, NE5532 and LM1458 and MC1458)...
Only the last 3 produce the funk effects. The best being lm1458.
But in any of them (the 3 that has funk sound), i loss a lots of volume there and i have to boost with a SHO.
You're running into a common problem with really old, vintage stomp boxes - they were poorly designed by today's standards, because the designers did not have the body of knowledge we do today. At the time the Seamoon was current, having even one effect in addition to a distortion was a rich pedalboard. The fifty-pound pedalboards we take for granted simply didn't exist.

In the case of the Seamoon, there are a number of what I'd consider design defects. To start with, it's neither buffered nor true bypassed, so it has the potential to be a tone sucker. That potential is fully expressed by that 50K pot which loads down the input whether the effect is bypassed or not. Using a bipolar transistor for a variable gain element works, kind of, but it is asking for distortion on any but the most quiet notes.

One of the specific problems you've run into is the same as the problem with the almost-identical and similarly benighted ElectroHarmonix DrQ. Compare the Seamoon to this https://www.diystompboxes.com/pedals/schems/doctorq.gif. The differences are trivial. In particular, they used the same opamp, the LM1458, which has a quirk which allows it to work with its inputs nearer the negative supply than most modern opamps that are not specified as single supply or rail to rail. Jack Orman expended part of his life correcting this with the Dr Quack: http://www.muzique.com/schem/quack.gif.

The Dr Quack does the obvious: it fixes the issues with the near-ground opamp input for the envelope, and it buffers the input so there's not so much tone sucking.
RG Thanks for the education...no doubt, this is a good place to learn...Thanks again.

Zurdo
Posts: 16
Joined: 20 May 2009, 12:10

Post by Zurdo »

I have a 1968 Seamoon Funk Machine. The above article is incorrect, the Seamoon company was founded in 1967, not 1970. 1970 is when they went out of business.
:applause:

it produces a "awh awh" sound as opposed to a "wah wah" sound.

Maybe this is the first Envelope Filter ever made? Made for Bass, not for guitar. The Mutron
III worked for both bass and guitar but was totally unreliable. This Funk Machine has been better at reliability although I haven't used it in years.
Attachments
Seamoon-Funk-Machine.jpg

User avatar
DiscoFreq
Resistor Ronker
Posts: 413
Joined: 13 Aug 2007, 11:56
Has thanked: 7 times
Been thanked: 26 times
Contact:

Post by DiscoFreq »

This is ALL SO WRONG!!!


Seamoon was founded after 1970 and existed until the late 1970's, I know people who worked for them around 1976.

Maybe the pots in your Funk Machine were made in 1968, but it's certainly made after 1970, the 1974 date in the book looks correct.
I have 2 Funk Machines, one like this (in a metal box) and an earlier one in a bakelite box (with the circuit in a block of goop).

The Mu-Tron III was first.

The reliability of the Seamoon products (pedals & amps) was a bad (no testing, poor construction,...), I NEVER heard that the reliability of the Mu-Trons was a problem.
EffectsDatabase: http://www.effectsdatabase.com
22000 pedals, 4000 brands, 350 brand interviews
NAMM 2016: http://fxdb.org/namm

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

The mutron isnt as predictable sounding as the regular hum drum ev's out there. but thats just my theory.
Skyline FX 2013

ohjustbyteme
Posts: 1
Joined: 31 Aug 2009, 16:42

Post by ohjustbyteme »

new user question. on the output of one of the 741's is a 1n4001 followed by a ? thats marked 100R is that a resistor? that clarification would be appreciated!
thank you
:slap:

jrod
Resistor Ronker
Posts: 416
Joined: 09 Jan 2009, 15:24
Has thanked: 337 times
Been thanked: 40 times

Post by jrod »

ohjustbyteme wrote:new user question. on the output of one of the 741's is a 1n4001 followed by a ? thats marked 100R is that a resistor? that clarification would be appreciated!
thank you
:slap:
Yup, that is a 100 ohm resistor.

User avatar
rhandy gaye
Solder Soldier
Posts: 174
Joined: 21 Apr 2008, 12:30
Location: TASMANIA Australia
Has thanked: 3 times
Been thanked: 20 times

Post by rhandy gaye »

there might be another mistake in the r.g. keen schematic (though probably not important).
the output cap .0047mfd listed in the schematic, looks more like .047mfd in all the different pics i've seen.
in the this pic, on the left above the .005 ceramic.
Attachments
DS00591813_3.jpg

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

Did anybody nab the trace side photo??
Skyline FX 2013

User avatar
rhandy gaye
Solder Soldier
Posts: 174
Joined: 21 Apr 2008, 12:30
Location: TASMANIA Australia
Has thanked: 3 times
Been thanked: 20 times

Post by rhandy gaye »

i've got some pics somewhere (i can't find them - too many friggin discs)

i have made a board from those pics but, i changed it a bit so a i can make version 1 and version 2, and so that there is not a resistor standing on end (like the original).

this is a head start though for those interseted.

please realize THIS BOARD IS SLIGHLTY DIFFERENT TO THE ORIGINAL (but very very close)

and i don't have the time to post a parts placement, it's not that hard to reverse anyway.

i can post a better quality pic of pcb later too.

cheers.
Attachments
seamoon copy.jpg

User avatar
rhandy gaye
Solder Soldier
Posts: 174
Joined: 21 Apr 2008, 12:30
Location: TASMANIA Australia
Has thanked: 3 times
Been thanked: 20 times

Post by rhandy gaye »

i found one pic, i know i've got atleast 3 more.
Attachments
is48954181551466.jpg

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

Very cool! Thank you :)
Skyline FX 2013

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

So I should be able to use a 1meg pot instead of searching for a 5meg'er I think. and perhaps raise the value of the 47K somewhat.

Perfboarded her today with a ge npn. Havent tested yet, :lol:
Skyline FX 2013

User avatar
rhandy gaye
Solder Soldier
Posts: 174
Joined: 21 Apr 2008, 12:30
Location: TASMANIA Australia
Has thanked: 3 times
Been thanked: 20 times

Post by rhandy gaye »

i'll post a parts placement in 2 days

cheers

User avatar
negrosinfe
Posts: 34
Joined: 02 Aug 2011, 00:50
my favorite amplifier: Marshall
Has thanked: 15 times
Been thanked: 3 times

Post by negrosinfe »

rhandy gaye wrote:i'll post a parts placement in 2 days

cheers
Can you post the part placements?

Thanx in advise,
negrosinfe
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)

User avatar
rhandy gaye
Solder Soldier
Posts: 174
Joined: 21 Apr 2008, 12:30
Location: TASMANIA Australia
Has thanked: 3 times
Been thanked: 20 times

Post by rhandy gaye »

hi, sorry i haven't done this, life gets in the way of things sometimes.

i will try really hard to find time and post parts placement by the end of the week.

cheers.

Post Reply