Hartman Analog Flanger  [traced]

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Hartman Analog Flanger

Postby bettsaj » 11 Sep 2017, 09:34

I'm looking at building an Electric Mistress clone, specifically a clone of the earlier 18v Mistress. i'm planning on drawing the schematic in Eagle and laying out a bespoke board in line with that schematic, and then buy a NOS SAD1024 chip off Ebay...... However, what might be a better solution would be to clone the Hartman Analog Flanger, however I've not found a schematic on the interweb, and images of the trace side are next to zero. Looking at the board pictures I've seen it's likely a 2 layer board???

Has anybody Dissected this pedal, and if so are there any schematics out there, or trace images. There seems to be a severe lack of information around this pedal.
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Re: Hartman Analog Flanger

Postby laughingcat » 20 Mar 2018, 22:13

I am wanting to build an Electric Mistress clone,
I have a couple of SAD-1024 NOS which I would trade for a PC board.
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Re: Hartman Analog Flanger

Postby numaxim » 04 Apr 2018, 16:17

hi, if it can help you, I built a ehx mistress a few days ago with mn3207 / mn3007.
the post you find it here ....

viewtopic.php?f=14&t=28907
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Re: Hartman Analog Flanger  [traced]

Postby soulsonic » 29 Apr 2018, 08:19

I repaired a Hartman Analog Flanger recently. It's an Electric Mistress clone, complete with SAD1024. So....just make an Electric Mistress clone...
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Re: Hartman Analog Flanger

Postby soulsonic » 29 Apr 2018, 08:20

Also, the Hartman was very poorly constructed. My "repair" was just resoldering these awful cold solder joints that had come undone and replacing the toggle switch with something that cost more than 50 cents. Shameful.
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Re: Hartman Analog Flanger

Postby bettsaj » 26 Jun 2018, 13:08

I have an update.... I have bought a fully functioning 1976 18v mistress PCB off a kind gentleman on the EHX forum for £50, that is minus the SAD1024 chip. Not a problem as i was given 2 SAD chips by a guy in Holland who had some NOS kicking around and didn't want them anymore. I just paid for the postage. So, I'm going to look at the board under scrutiny and document the component values, and photograph it. i'll likely post the results here.

Until then here's a photo of the board currently.... The guy i'm buying it off mounted it in a rack, and hasn't used it in years so it's just gathering dust

a very old Mistress.jpg


My intention then is to create a PCB trace layout from that board. I've been corresponding with Brook at Pigeon FX and he's interested in dissecting one as he's not had a chance to really look at a Mistress board in any detail. He may offer it as a PCB in the future.
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Re: Hartman Analog Flanger

Postby Scruffie » 26 Jun 2018, 13:27

If I was you, I wouldn't try and recreate that layout and go with the V5 instead, it's exactly the same circuit (apart from one additional cap on the back of the board and the improved voltage regulator) but its severely improved regards noise, the V1-4 had very long and intertwining traces which really didn't help with the ticking problem these units have, recreating it for offering a PCB would be a bit of a waste of time IMO, too many major quirks despite the otherwise lovely sound.

They also hugely benefit from the addition of a filtering cap added to the inverting stage at the input (the same as found in the 9V version) this reduces the large amount of aliasing noise the early versions had and for actual usability is a pretty invaluable mod, it does reduce the highs of the dry signal a hair but it's a worthy compromise.

I don't know if you also intend to use the volume drop compensation mods available on the net but these either affect the wet/dry balance which are key to getting the best flange sound or if its increasing the input gain, you reduce the headroom of the BBD significantly so you should really be considering an output boost.

Edit: There's a few oddities with these circuits too, the VCO changes slightly between units with some having a much higher clock frequency (35 minimum instead of 20 IIRC which leads to a lot less noise but a different sound) and for some reason I never did work out I could never get the full 10:1 sweep range the originals would read when recreating the circuit, I even tried vintage 4013, although not a vintage 339.

Edit2: Oh and the Hartman was a 9V mistress clone, not 18V.
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Re: Hartman Analog Flanger

Postby bettsaj » 26 Jun 2018, 16:07

I may do that actually... That's a good idea to do the version 5.

I'll still create a trace layout for this version 2..... I might as well as long as I have it in this state before I build it into an enclosure and use it.

Regarding the volume drop mod.... Have you seen Blondegraemeys mod on YouTube....... a 10k resistor and a tantlium capacitor (can't remember the value, you'll have to check) soldered onto the trace side of the board. That doesn't sound too bad to be honest... Not sure what it's doing though..... Maybe you can shed some light on it


Link
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Re: Hartman Analog Flanger

Postby Scruffie » 26 Jun 2018, 16:13

Seen it? I have one of Graemey's units :D Yes it does sound 'okay' but there was definitely more dry signal with it and not the 50/50 mix the values were chosen for, so the flange effect wasn't as deep as it should be.

If I remember I think I have some shots of the V5 saved that I can send to Brook.
Last edited by Scruffie on 26 Jun 2018, 16:18, edited 1 time in total.
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Re: Hartman Analog Flanger

Postby bettsaj » 26 Jun 2018, 16:18

I'll be running the flanger through a loop in my audio switcher, so it'll be easy to just put a boost pedal after the flanger to bring the volume up in the same loop.... That way the boost will only be on when the flanger is engaged.

Any suggestions on a simple boost.... something that I can make that just gives a clean boost with a small footprint?
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Re: Hartman Analog Flanger

Postby Scruffie » 26 Jun 2018, 16:22

An inverting opamp will provide the cleanest simplest boost and have the mistress be in phase.

See the edit I made above, ask Brook to shoot me a message, he knows me.
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Re: Hartman Analog Flanger

Postby bettsaj » 26 Jun 2018, 16:30

Will do..... Just seen your edit. I've actually just downloaded a good picture of a v5 off the interweb from an old eBay auction, see below:

v5 pcb.jpg



Regarding the opamp boost, can you suggest any particular one?... I have the schematics of a few, but in all honesty wouldn't know what is the best for my purposes. I suspect a transparent boost that doesn't colour the tone,
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Re: Hartman Analog Flanger

Postby Scruffie » 26 Jun 2018, 16:37

Literally just a bog standard inverting op amp set up for gain, like this Image

Pin numbers are wrong for most single op amps and you'd want R2 to be a trim but otherwise, basically that.
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Re: Hartman Analog Flanger

Postby bettsaj » 26 Jun 2018, 16:59

Yeah... pretty simple.... never worked with op amps before, so this'll be a first

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Re: Hartman Analog Flanger

Postby bettsaj » 26 Jun 2018, 17:21

Just done a recky, and I think I'll have a go at this

mxr-microamp-schematic-small.png


MXR MicroAmp... Looks like a good clean transparent boost pedal.... And best of all.... Simple.

https://www.electrosmash.com/mxr-microamp
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Re: Hartman Analog Flanger

Postby Scruffie » 26 Jun 2018, 17:32

That will work fine if you prefer it, although it is higher parts count than my suggestion and going at the end of the mistress the input impedance is far higher than it needs to be which could increase noise, also if it's always 'on' it doesn't need the input anti pop resistor.
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Re: Hartman Analog Flanger

Postby bettsaj » 26 Jun 2018, 19:33

Yeah... Thanks for that, but I'm also thinking or elsewhere can use it if i'm not using the mistress
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