Search found 208 matches

by valgamaa
Thu May 30, 2019 12:49 pm
Forum: 5U Format Modules
Topic: krisp1 TZ VCO
Replies: 44
Views: 3886

Re: Trim pots

How do you carry out the calibration of the Krisp1 TZVCO? There are seven trimpots on the back. What adjustment are they used for? Here is a picture of the back: Aligning the VCO requires an oscilloscope and some way to measure frequency, so shouldn't be attempted unless you have the right equipmen...
by valgamaa
Sat May 18, 2019 1:20 pm
Forum: 5U Format Modules
Topic: krisp1 TZ VCO
Replies: 44
Views: 3886

unless I have memory bleach.. valgamaa Designed the Krisp TZ .. so he may know a little.. :) I hope he will comment. If I have a defective module, I'd like to confirm in some way. Happy to comment, but I got home from SuperBooth at midnight on Sunday, and went to Helsinki for the week at 6.30 on Mo...
by valgamaa
Sat May 18, 2019 1:11 pm
Forum: 5U Format Modules
Topic: krisp1 TZ VCO
Replies: 44
Views: 3886

unless I have memory bleach.. valgamaa Designed the Krisp TZ .. so he may know a little.. :) I hope he will comment. If I have a defective module, I'd like to confirm in some way. Happy to comment, but I got home from SuperBooth at midnight on Sunday, and went to Helsinki for the week at 6.30 on Mo...
by valgamaa
Wed May 15, 2019 2:17 pm
Forum: 5U Format Modules
Topic: krisp1 TZ VCO
Replies: 44
Views: 3886

But, what is Through Zero? As it happens, the Krisp1 TZ oscillator responds appropriately to linear FM pitch control BUT does not produce an inverted waveform from negative control voltages. (This usually has no audible impact.) Wrong. The VCO, like all TZ-VCO's reverses the waveform when zero-freq...
by valgamaa
Fri Jun 22, 2018 3:55 am
Forum: Music Tech DIY
Topic: Euro module power protection. How?
Replies: 20
Views: 1850

Altitude909 wrote:Bridge rectifier so it doesnt matter which way you plug it in.
That will only work on a 10-way header, 16-way gets a little more complicated.
by valgamaa
Wed Jun 20, 2018 8:23 am
Forum: Music Tech DIY
Topic: Mini-Modules : Minimoog DIY clone on its way.
Replies: 1945
Views: 277588

The capacitors are 220uF on each rail. The large cap on the right is the input filter from the data sheet (with the inductor next to it). My MIDI interface only requires 3mA, so I chose the line of least resistance (I didn't have a 78L05) to hand. Of course, there is nothing to stop anyone fitting t...
by valgamaa
Wed Jun 20, 2018 7:56 am
Forum: Music Tech DIY
Topic: Mini-Modules : Minimoog DIY clone on its way.
Replies: 1945
Views: 277588

I have been putting the finishing touches to my MME, and have turned my attention to case, PSU and MIDI interface. For the case I have chosen the Moog 60HP one, and have made some PCB's for the PSU. The mounting holes are spaced so that it will fit the internal rails with tubular spacers and self-ta...
by valgamaa
Tue Apr 24, 2018 9:15 am
Forum: Eurorack Modules
Topic: Liivatera modules
Replies: 15
Views: 1509

I just picked up one of his Quadrature LFOs and I love it. Not sure if he's still making them, but I highly recommend it if you can find one. https://www.modulargrid.net/e/liivatera-quadrature-low-frequency-oscillator The Quadrature LFO is still in production and stocked by Escape from Noise and Sc...
by valgamaa
Thu Aug 10, 2017 1:13 pm
Forum: Music Tech DIY
Topic: TL072 vs. TL082... sound and noisefloor
Replies: 37
Views: 42063

Re: TL072 Pinout details

TEPJunaid wrote:may be we can't replace it but TL072 pinout can help you alot in this case.
Image
Pin 4 is actually the negative supply, not ground.
by valgamaa
Thu Jul 06, 2017 10:35 am
Forum: 5U Format Modules
Topic: Krisp1 OCTO MU VC-Quadrature LFO Now in stock
Replies: 68
Views: 6361

..cambridge is still not "just round the corner " :) drive to cambridge and show them off to a few people or do a video that everyone can watch anytime..? personally I know what I would be doing... :) a no sound video that I cant see/find eh.. perfek .. not exactly the hard sell ..:) London to Camb...
by valgamaa
Thu Jul 06, 2017 9:38 am
Forum: 5U Format Modules
Topic: Krisp1 OCTO MU VC-Quadrature LFO Now in stock
Replies: 68
Views: 6361

..it a bit like saying is a pair of shoes or cheese or a car..you buy one over the others for features quality etc.. like every single product in the world ever.. I would like to see the spinning lights .. hear the compression and hear the changing waves and how they effect the sound.. why is that ...
by valgamaa
Thu Jul 06, 2017 9:33 am
Forum: 5U Format Modules
Topic: Krisp1 OCTO MU VC-Quadrature LFO Now in stock
Replies: 68
Views: 6361

saw that.. :) its great..thanks John !(shame about the osc he modulating) pauls has a compression feature as well which I would also like to see/hear .. this erica gives the idea... but still think its wise to present your own stuff or have someone do it.. call me mental. on a side note.. Wed Feb 0...
by valgamaa
Wed Jul 05, 2017 11:22 am
Forum: 5U Format Modules
Topic: Krisp1 OCTO MU VC-Quadrature LFO Now in stock
Replies: 68
Views: 6361

josaka wrote:just want to hear it before coughing up..:)
It's an LFO, so not much to hear. Paul has put a few views on his Krisp1 FB page, and there are pictures and some conversation there too. That should have all that you want.
by valgamaa
Thu Feb 09, 2017 4:41 am
Forum: Modular Synth General Discussion
Topic: LP+HP vs Allpass
Replies: 7
Views: 635

This note gives some useful equivalents in equation 2 -
http://www.analog.com/media/en/training ... MT-202.pdf

HAP =HLP –HBP +HHP =1–2HBP
by valgamaa
Fri Nov 11, 2016 4:10 am
Forum: Music Tech DIY
Topic: Alpha Pots vs. BI Technologies / TT Electronics
Replies: 21
Views: 2596

I have used these pots for years, but only use pots in places where I want a ratio, I would never rely on a pot for absolute resistance. By ratio, do you mean pot on all 3 nodes of an inverting amplifier config opamp? i.e. from output to -ve input terminal , and from -ve input terminal to input sig...
by valgamaa
Wed Nov 09, 2016 1:29 pm
Forum: Music Tech DIY
Topic: Alpha Pots vs. BI Technologies / TT Electronics
Replies: 21
Views: 2596

slow_riot wrote:Anyone know the tempco on them? Lots of conductive plastic pots that I've seen are around +/-1000PPM . No figure given in the Bi Tech datasheet.
I have used these pots for years, but only use pots in places where I want a ratio, I would never rely on a pot for absolute resistance.
by valgamaa
Mon Aug 29, 2016 12:05 pm
Forum: Music Tech DIY
Topic: STM32 correct orientation?
Replies: 7
Views: 767

The ST datasheet has a diagram showing the pin 1 and includes the chip text in the picture to remove all ambiguity. The pin 1 ident is the one that is top right when the text is upside down.
by valgamaa
Thu Jun 23, 2016 7:58 am
Forum: 5U Format Modules
Topic: Krisp1 TZ-VCO
Replies: 28
Views: 2176

Right on... Estonia, home of Arvo, as well. Kind of the same as this, then? http://www.liivatera.com/Products/Synthesisers/TZ_VCO/ yup with in my opinion a few improvements as the larger PCB allowed for said improvements :) The differences between the two oscillators are - Different transistors use...
by valgamaa
Sun Feb 21, 2016 1:13 pm
Forum: Eurorack Modules
Topic: Dead Mungo modules?
Replies: 311
Views: 19730

It is obvious that you have not looked at these modules in any depth, as the 5V supply rail is connected to components that will be damaged/destroyed if they are supplied 12V. When a 16 pin module is connected in reverse on a power supply the 12V and 5V rails are shorted together, this has caused p...
by valgamaa
Wed Feb 17, 2016 2:28 pm
Forum: Music Tech DIY
Topic: Velleman Audio Analyzer kit?
Replies: 1
Views: 245

I bought one of these a few years ago as entertainment over the Christmas break. It works well enough for what it is - from memory the processor is a DSPic, but don't expect a proper spectrum analyser. I haven't found any use for the module since building it, but didn't expect to either. I wanted a ...
by valgamaa
Sun Jan 03, 2016 7:05 am
Forum: Aether Machine
Topic: Oscilloplasm - complex VCO pair
Replies: 157
Views: 26279

Thanks for checking in on my activity and subjecting my little world to some fair objective analysis! It can be easy to get a bit carried away with ones own mindset. :) I know the feeling! The objective is for the most "beautiful" design, which is of course a very subjective choice. Having used var...
by valgamaa
Sun Jan 03, 2016 6:38 am
Forum: Eurorack Modules
Topic: Pitch Calibration in Eurorack is a pain in the ass
Replies: 101
Views: 12808

When scaling a VCO to match the MIDI-CV source that I have (which is of course not quite the same as setting 1v/Oct scaling...) I use a quick and simple method that works well for me. I start by initially tuning the VCO to 440Hz by zero-beating the VCO and a crystal-derived 440Hz reference in a mixe...
by valgamaa
Fri Jan 01, 2016 6:44 am
Forum: Aether Machine
Topic: Oscilloplasm - complex VCO pair
Replies: 157
Views: 26279

The 8903 wouldn't behave well under voltage control, certainly under FM, maybe there's a better way to implement it than HP did though. Still a board of noisy digital circuitry and non ideal performance though. That's not entirely fair - the 8903 is designed for a specific purpose unrelated to modu...
by valgamaa
Mon Nov 16, 2015 2:13 am
Forum: Eurorack Modules
Topic: z3000 problem (power problem?)
Replies: 21
Views: 1254

Hey guys, Problem solved. Rather small mistake. Ofc the ground on the Doepfer Bus Board has to be connected to generate the -12V. Here my power supply. It's a Meanwell RT-65 - runs like a charm, no noise no troubles... great! :) http://s3.postimg.org/fjw4qugdf/chris_BA_WP_20151115_001.jpg Thanks a ...
by valgamaa
Thu Oct 15, 2015 2:20 pm
Forum: Fractional Rack Modules
Topic: Frac Rack Prototyping PCB
Replies: 5
Views: 1640

fracmonkey wrote:You might get VAT taken off for US shipment; maybe 20%
That's correct, use the code VAT Refund and it is all done for you. Of course, anyone that tries that when VAT is applicable won't be so fortunate!

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