freestompboxes.org

Rumored to contain some sort of tube emulating analog circuitry. Could be interesting to know at least something about it
http://www.dual-drive.de/index_e.htm


There is only one demo which is not so fun but at least show a bit of the clipping sound character with low/medium gain and a strat

http://www.dual-drive.de/Demos/dualdrivedemo01.mp3

The 5 buyers/reviewers here seem quite satisfied
http://reviews.harmony-central.com/revi ... Drive/10/1

i have an old black one. very great sounds. but is slightly gooped. most of the components are SMD, dual-layer-PCB.
but i will never degoop my DD for two reasons; Dirk B. created a genius-pedal and i will respect him. and is too expensive for destroy it

the newer ones are not gooped.

this pedal is not only low/mid-gain, it sounds very good on hi-gain!
Dirk offers some modifications for the new red DDs; hot marshall- , DualRecto- , SLO100-Style... maybe i sell my old version and buy a new modified, the original could sound a bit "harder" for my kind of music.

maybe we could find his patent in the internet?

regards,
ksui

Just had a quick listen to the .mp3. I wouldn't say that it sounded bad, and perhaps fine for a live coverband type thing but DD seems kind of anemic to my ears based on the clip.
It would be nice to know what the recording chain is in order to evaluate the mp3!

I'm not saying I don't want to know what's in the DD!

k**i wrote:i have an old black one. very great sounds. but is slightly gooped. most of the components are SMD, dual-layer-PCB.
but i will never degoop my DD for two reasons; Dirk B. created a genius-pedal and i will respect him. and is too expensive for destroy it

the newer ones are not gooped.

this pedal is not only low/mid-gain, it sounds very good on hi-gain!
Dirk offers some modifications for the new red DDs; hot marshall- , DualRecto- , SLO100-Style... maybe i sell my old version and buy a new modified, the original could sound a bit "harder" for my kind of music.

maybe we could find his patent in the internet?

regards,
ksui

Thanks for the report kusi. Patent? Is that perhaps at the german patent office then?

hi goop_buster,

i searched a long time about this patent on the internet, but i found nothig... and dirk doesn`t answer questions like this

the technology is called "analog tube modelling" (written on the pedal-case). the inventor should be dirk baldringer. maybe the patent is saved with another name/inventor?

somewere i heard, that the basically technology is build as a special custom IC in the new red pedals. (like the V-stack-pedals). but i don`t know if this is true.

regards, kusi

maybe it is like the old HH valve sound (VS musician series) circuit - a distorted jfet - ho hum
bajaman

Analog Tube Modeling? There is no need, tubes already are analog, maybe he means 'Digital Tube Modeling'

Ok Kimosabi, you don't have to degoop that one -- Lots of knobs and a big box -- I suppose SMD is another legitimate way to protect your circuit.
But how do you know it's patented at all? I wouldn't take that for granted.

It looks good, but that hardly ever means anything...

mm

I don't think there a patent for the circuit and to be safe you must have world wide patents for it. How many DDs must Dirk sell to get the fees back?

JHS

here are two gut-shots of the red version;

http://cgi.ebay.de/ws/eBayISAPI.dll?Vie ... otohosting

black top-overlay... but the traces are visible. for better reverse-engineering-protection, i would use some mid-layers

does anybode know something about his patent if it realy exist? (and if it does, why does he try to hide the circuit??)

regards, kusi

Hey Kusi... how are you. Have you got Larry amp?
I can say only good about Baldringer DD... DD is very good... but wasn't the be-all-end-all pedal for me. And communication with Dirk is not the best. I tried to get Red version modded for HotRod Marshall but got no answer. To me it sounded like my Fetto 11.1, kinda 80th style and I wish it has wider eq ability.

Hey thanks Ravi
I built it on veroboard this morning - the negative feedback inverting op amp configuration (I used a 2SK117 as a high impedance buffer input stage) and checked out a 1khz sine wave on my scope. As I wound the signal level up I noticed a very similar shaped distortion on the top half of the waveform to my Baja Real Tube Overdrive. As I continued to wind the signal level up, the bottom of the wavefom started to distort - again like my Real Tube Overdrive but a lot earlier. I am sure that by playing around with the voltage divider resistors before the NPN (or is it the PNP )transistor I can delay the onset of clipping on the bottom half of the waveform. This looks most interesting - I will do some more research as the time permits . I must emphasise - I Have not HEARD this yet - but it does look much more promising than the tired old fuzzy clipping diodes (whatever type turns you on) or the endless jfet amp models, neither of which give a convincing tube overdrive sound to my ear.
More later - thank you so much for your link
bajaman

Baja Real Tube Overdrive, mhhh...
if I get some time!

bajaman wrote:Hey thanks Ravi
I built it on veroboard this morning - the negative feedback inverting op amp configuration (I used a 2SK117 as a high impedance buffer input stage) and checked out a 1khz sine wave on my scope. As I wound the signal level up I noticed a very similar shaped distortion on the top half of the waveform to my Baja Real Tube Overdrive. As I continued to wind the signal level up, the bottom of the wavefom started to distort - again like my Real Tube Overdrive but a lot earlier. I am sure that by playing around with the voltage divider resistors before the NPN (or is it the PNP )transistor I can delay the onset of clipping on the bottom half of the waveform. This looks most interesting - I will do some more research as the time permits . I must emphasise - I Have not HEARD this yet - but it does look much more promising than the tired old fuzzy clipping diodes (whatever type turns you on) or the endless jfet amp models, neither of which give a convincing tube overdrive sound to my ear.
More later - thank you so much for your link
bajaman

Can't wait for your sound report

hey guys,

any news on this topic? it would be very interessting.....btw; did someone know an alternative/similiar to this baldringer dual drive pedal?

thanks

raffa

With component values given for the patent's schematic the circuit has indeed designed asymmetry and it can be controlled with the ratio of those voltage dividers at the transistor's bases. The design is based on transistors that are driven to conduct and provide additional negative feedback signal, consequently lowering the gain and "clipping" the signal. I've seen this before but can't recall where (likely in some Warwick amp). The clever part, IMO, is that Baldringer threw in a hi-pass filter as a part of the voltage divider that is shared by both transistors. With this, the level of overdrive is frequency dependent and the circuit is not producing the ordinary "buzz" of most diode / transistor based solutions that work on a fairly wide bandwidth.

I doubt the circuit as itself sounds anything impressive. It will be a wholly different thing when you cascase two or three of them and throw in some carefully designed filtering for pre and post OD tone voicing. That, of course, is not shown by the patent.

hey teemuk,

thanks for the answer....did you see any gutshots?

cheers raffa

Does anyone have any more information on this? What would be values of the resistors, and capacitors to try this out with?

Oops, never mind. They are on the patent link.

I seem to have lost my print out of the patent page, does anyone have a copy? Any more news on RE'ing this?

Thanks
Rob