Hermida Audio - Zendrive [ goop-alarm ]

Post by **pamaz** » 07 Sep 2010, 20:04

seems that is a self oscillation.
it happens also on the normal zen sometimes.
BTW it's a not normal condition of use, so don't bother yourself too much for this.
The self oscillation is tamed by lowering the volume or the tones control.
.
Paolo

LooseCannon · Post by **LooseCannon** » 20 Sep 2010, 21:17

Hey guys, could anyone recommend me a kit for the Zendrive?

The only one I know of is this one: http://uk-electronic.de/onlineshop/prod ... e4bfd1fde4

It seems a bit expansive at $70 including a drilled enclosure. Would it be cheaper if I ordered all of the parts instead of buying a kit?

Also, how accurate is that kit? Check out this pdf with the parts listed: http://www.uk-electronic.de/Download/Be ... ndrive.pdf

After checking out this thread everything seems to be right except for some of the diodes. Could anyone confirm this?

I don't know which brands they're using for the caps as well, or if that would make a significant difference.

Thanks in advance!

eniacmike · Post by **eniacmike** » 21 Sep 2010, 05:30

It is cheaper to order the parts separately.

You can get a really nice fabbed pcb from madbean http://www.madbeanpedals.com/projects/index.html the serendipity pcb is only $8. I built it up following his instructions and it sounds fantastic. I doubt it was more than $50 in parts total to build it up.

B_of_H · Post by **B_of_H** » 21 Sep 2010, 17:58

i built this one using madbeans pcb. I ended up taking D1 and D2 out as they seemed to make the circuit sound compressed and fake to me.

the ad712 sounds the best with all the clipping diodes but after taking those two out I like the burr brown opa2604 the best so far with the tl072 my second favorite. The ad712 is very sterile and articulate but a little too much so at lower gain where I'm wanting to run the pedal. (tried opa2134, lm1458, 4558, ne5532, and a few others)

I liked the voice control about 7k3 so I just put in a resistor that was close and got rid of that control. anything above about 7k seemed to thin out the bass response so it sounded 'tinky'.

I raised C2 to 220p and this tamed a tad of the shrillness I think. I'm going to keep plugging around with it, great circuit. I'm not looking for the dumble like sound though and I wanted something between a TS808 and an OCD and this is pretty damn close so far.

I may lower the pulldown a tad and mess around with the treble roll off cap next.

roseblood11 · Post by **roseblood11** » 21 Sep 2010, 18:43

It seems a bit expansive at $70 including a drilled enclosure. Would it be cheaper if I ordered all of the parts instead of buying a kit?

There´s a bill of materials included - get out your calculator!...

If you are able to build the Zendrive without a kit, do it. If you aren´t - pay for the kit

)
But I agree that Uwes prices for distortion pedals are a bit strange: Dod 250 - 20€; Big Muff - 30€; Zendrive - 43€. That´s capitalism, I guess...
The kit is accurate except for the gain pot, which is 1M instead of 500k, what gives you twice the max. gain of an original Zendrive - a very good decision! Diode configuration is 100% accurate (I have built the pedal using that kit!)

There´s a Veroboard-Layout by "gila_crisis" over at the diystomp gallery:
http://aronnelson.com/gallery/main.php/ ... ewsIndex=1
"D1" should be a germanium (1n34a, 1n60 or similar), the rest looks correct.

I liked the OPA2604 much better than the AD712, followed by OP275 and NE5532AP. TLC2262 or 2272 are said to sound great as well.

I´d never replace the voice-control with a fixed resistor, I think it´s the most useful control of the pedal. I even implanted that control into a Mad Prof Sweet Honey Overdrive - great improvement!
If you turn the pot cw, it raises the gain and lowers the bass (not only above 7k

)

@BofH: Shrillness? In a Zendrive? And to your ears it sounds "in between a TS808 and an OCD"? We have totally different ears...

regards, Immo

LooseCannon · Post by **LooseCannon** » 22 Sep 2010, 00:30

Thanks guys.

Roseblood: my problem is that i'd have to order the parts from 2 or 3 different sources, since I need a drilled enclosure, and the pcb, unless i'll go with your veroboard suggestion. Is there one store I could get all of the parts I need from?

Another problem is that i'm not sure which caps\restistors types\brands I need. Do you know exactly which ones are on the original zendrive?

Regarding the veroboard, i've never worked with one, how do I create the traces between the different componets? Or are there traces built into the veroboard? Also what is the difference between veroboard\breadboard\perfboard?

Regarding the diodes, I have read that on the original zen there are two bat46's and one 1n34a in the clipping section, is this not correct?

Thanks in advance!

roseblood11 · Post by **roseblood11** » 22 Sep 2010, 09:03

Many typical beginners questions.

-> Why don´t you buy the kit? I don´t know who else sells pre drilled enclosures...
That would spare us all a nerve-jangling debugging process

Diodes: It doesn´t matter if you use BAT41 or BAT46, both are shottkys and will sound exactly the same. And you can use any other Ge-Diode to replace the 1n34a. Or try completely different Diodes (1n4148, 1n4001, LED´s...) - your ears decide!

Caps: Looks like Panasonic Polyester Caps, maybe SMF series. Any other Polyester film cap will definitely produce the same sound. Buy small ones (SMF are very small). The little cap in parallel with the diodes has a little influence on the sound - try ceramic, silver mica or film caps there.

Resistors: Hermida uses cheap Carbon Resistors, I´d suggest to use metal film. Same sound, maybe a bit less noise.

You can buy all parts from all big (or specialized) suppliers. Mouser, Farnell, Small Bear, Banzai, uk-electronic, musikding ...

B_of_H · Post by **B_of_H** » 17 Jan 2011, 17:32

roseblood11 wrote:
It seems a bit expansive at $70 including a drilled enclosure. Would it be cheaper if I ordered all of the parts instead of buying a kit?
There´s a bill of materials included - get out your calculator!...

If you are able to build the Zendrive without a kit, do it. If you aren´t - pay for the kit )
But I agree that Uwes prices for distortion pedals are a bit strange: Dod 250 - 20€; Big Muff - 30€; Zendrive - 43€. That´s capitalism, I guess...
The kit is accurate except for the gain pot, which is 1M instead of 500k, what gives you twice the max. gain of an original Zendrive - a very good decision! Diode configuration is 100% accurate (I have built the pedal using that kit!)

There´s a Veroboard-Layout by "gila_crisis" over at the diystomp gallery:
http://aronnelson.com/gallery/main.php/ ... ewsIndex=1
"D1" should be a germanium (1n34a, 1n60 or similar), the rest looks correct.

I liked the OPA2604 much better than the AD712, followed by OP275 and NE5532AP. TLC2262 or 2272 are said to sound great as well.

I´d never replace the voice-control with a fixed resistor, I think it´s the most useful control of the pedal. I even implanted that control into a Mad Prof Sweet Honey Overdrive - great improvement!
If you turn the pot cw, it raises the gain and lowers the bass (not only above 7k )

@BofH: Shrillness? In a Zendrive? And to your ears it sounds "in between a TS808 and an OCD"? We have totally different ears...

regards, Immo

yeah, I was referring to the sound differences of the ad712 as opposed to other dual opamps not this circuit itself, sorry for the confusion. I ended up modding mine to closer to 'son of screamer' specs anyway and put the voice control back in (I raised a cap value to let more bass through)

roseblood11 · Post by **roseblood11** » 18 Jan 2011, 00:16

I use a TLC2272 and run the pedal at 12V now. But it´s sitting on the shelf most of the time. I think the Zendrive is highly overrated. For lead playing there are many pedals that have much better dynamics (ROG Umble...), for rhythm a simple Tube Screamer does a better job for me.

jhreid · Post by **jhreid** » 23 Jan 2011, 18:29

Hey all. I've just taken delivery of the uk-electronic kit. First impressions are a really high quality PC - good and thick with through plated holes. Standard b sized undrilled enclosure. Will post pics this week and happy to report back on the build, when I get it started.

jocro · Post by **jocro** » 27 Jan 2011, 18:55

New to the forum, 1st of all, Thanks to all who contributed to all the effort involved with the Zendrive. Lots of great info here, was also thinking of buying the uk-electronic kit but was directed to a Euro version of paypal, I'm in the US and wasn't quite sure what to do with it once I was directed there. jhreid, if it's not to late maybe you could post a shot of the pc board less components. Anyway, was also curious about the layout for the extra components on the uk version, here is a pic of the board and a vid of what it sounds like.
Thanks Again

: uk-electronic zendrive kit board

jhreid · Post by **jhreid** » 12 Feb 2011, 11:25

Sorry for the delay, but finally got to opening and starting on the kit. Here are some pictures:

Track side of board

Component side of board

Populated board

Instructions in German, but not too difficult to make sense of. Need to get the enclosure drilled now ...

John

roseblood11 · Post by **roseblood11** » 12 Feb 2011, 13:07

yupp, that kit is great. That was my first diy effects pedal.
But the prize really shows that Uwe (who grew up in east germany...) understands capitalism

43€ for a Zendrive, 30€ for a Big Muff, 20€ for a DOD 250

Strange...
btw: Uwe sells drilled enclosures for some of the kits, the zendrive is one of them.

The pcb is really well made. Unfortunately, he doesn´t sell it separately (but he offers some other pcb´s, including an interesting version of the PT-80 Delay with voltage doubler).

jay42 · Post by **jay42** » 12 Feb 2011, 18:38

pamaz wrote:seems that is a self oscillation. It happens also on the normal zen sometimes. BTW it's a not normal condition of use, so don't bother yourself too much for this. The self oscillation is tamed by lowering the volume or the tones control.

I built one a while back and noticed a slowish oscillation...sort of 2 or 3Hz swirl near 200 to 300Hz. It wasn't very loud and I hadn't noticed it before. I thought it might be a lead dress problem. Is that also typical?

Cannibal · Post by **Cannibal** » 14 Feb 2011, 20:49

I've build a zendrive on perfboard using frequencycentral layout(many thanks to him). After trying the standard version i've made some changes: 1meg for drive pot and a switchable clipping section with a on-off-on dpdt (mosfet, mosfet body diode and diode lift). I still haven't tried this changes, so this layout is still unverified (should work, if there are some mistakes point it out please).

aflynt · Post by **aflynt** » 15 Feb 2011, 18:41

I built one of these over the weekend using Madbean's Serendipity board. I subbed a 1n34a for D2 instead of the BAT41, but otherwise followed the schematic on his site exactly. Having never heard an original I can't comment as to how close it actually is, but I definitely prefer it to all the other overdrives I've tried and built and used over the years. I love how smooth and big it sounds and how well it reacts to the way you pick.

-Aaron

quaternotetriplet · Post by **quaternotetriplet** » 16 Feb 2011, 11:09

aflynt wrote:I built one of these over the weekend using Madbean's Serendipity board. I subbed a 1n34a for D2 instead of the BAT41, but otherwise followed the schematic on his site exactly. Having never heard an original I can't comment as to how close it actually is, but I definitely prefer it to all the other overdrives I've tried and built and used over the years. I love how smooth and big it sounds and how well it reacts to the way you pick.

-Aaron

nice labels. what do you call that type of material.

aflynt · Post by **aflynt** » 16 Feb 2011, 14:00

nice labels. what do you call that type of material.

I used these for the label:

http://www.texascraft.com/hps/product.p ... 271&page=1

-Aaron

cisjga · Post by **cisjga** » 01 Jun 2011, 22:35

Roseblood11,

I am very interested in your comparison of the Zendrive to the ROG Umble. I have built and modded several Umbles myself and consider it to be the Holy grail for me and the people that I have buit them for anyway.

Personally I find the Ubmle to be very organic, extremely tube-like more so than any other pedal I have ever encountered. I have never actually had the chance to build a Zendrive or even play an original one for that matter but I am contemplating it. However if the Umble is a more realistic Dumble emulator than the Zendrive then I can't see why I should bother with it.

ilpfis · Post by **ilpfis** » 04 Oct 2011, 06:57

Hi,
What is the manufacturer of this capacitors those red in the picture? they are very similar to those used analogman or robert keeley.
Thanks

Hermida Audio - Zendrive [ goop-alarm ] [traced]