Valvecaster troubles

iccaros · February 21, 2012, 06:47:16 AM

I have had zero problem with electro-harmonix

paulyy · February 21, 2012, 07:25:35 AM

Quote from: iccaros on February 21, 2012, 06:47:16 AM
I have had zero problem with electro-harmonix

+1 They sound great in a valvecaster.

seedlings · February 21, 2012, 09:39:36 AM

Quote from: MichelP on February 19, 2012, 09:23:08 AM
This is probably the answer you´re not waiting for...
The JJ ECC82 doesn´t function well in the valvecaster knock off´s I´ve made. Several discussions on a German forum (Tube-Town) also suggest that the JJECC82 doesn´t work with the topology of the valvecaster.
But don´t throw away that JJ tube ! It functions flawlessly with a higher anode voltage (> 32 V) or if you want to stay with 12 V you can build a nice clean booster with it !
I built a nice clean tube-booster by putting a JFET buffer before the tube line stage mentioned in Merlin Blencowes article "Triodes at low voltage" schematic fig. 9.
With this I tried several brands and types of tubes (EH12AU7, China12AU7, 5963, nos Philips ECC81, JJ ECC81 and JJECC82) : best sound -> JJECC82 !
Web links
http://www.muzique.com/lab/buffers.htm
http://www.freewebs.com/valvewizard2/Triodes_at_low_voltages_Blencowe.pdf

I JUST bought two JJ ECC82s.... for a 15V valvecaster. With a dozen 12AX7s and 6FQ7s new and old, I figured one of them would sound good, but most of them sound like a mis-biased transistor. One 12AX7 sounds OK, but not right. So I go online and order some JJs. And THEN I read this... Doh.

Shouldn't the JJ be spec'd identical (probably made in the exact same factory) as other 12AU7 types?

CHAD

danamoose · February 22, 2012, 09:57:22 AM

I dont know about the same factory but I would have thought also that being the same model tube there tolerances would be about the same. I guess we'll see what happens. I have an RCA tube on its way from a generous forum member (thanks again Larry) and also have ordered an EH 12au7 based on the other suggestions above. Will let you know what happens. This is my last attempt before tearing it all apart and rebuilding it on my fancy new breadboard!

Lesson learned to prototype it on the breadboard before building in to the actual board.

live and learn!

iccaros · February 22, 2012, 10:13:09 PM

@12 volts you are way out of specification. NOS tubes work really well in this, as it is rumored that the 12u7 (a tube made for 12v) is a 12AU7 in real life.

so while they are very close at 200v they are worlds apart at 12..

seedlings · February 22, 2012, 10:41:40 PM

Quote from: iccaros on February 22, 2012, 10:13:09 PM
@12 volts you are way out of specification. NOS tubes work really well in this, as it is rumored that the 12u7 (a tube made for 12v) is a 12AU7 in real life.

so while they are very close at 200v they are worlds apart at 12..

After thinking about this for a while, and a little Oogle searching, I wonder, does this site mean JJ and EH are both made by NewSensor?

http://www.newsensor.com/

CHAD

kurtlives · February 22, 2012, 11:19:08 PM

Have you used your DMM and checked for continuity through the circuit and checked it versus the schem?

Also I see your using perf while the layout you linked to is a vero layout. That can be confusing for a first build.

Anyways it looks like your shorting out the red resistor (C1) in the layout. Can you check this.

Chris...

PRR · February 23, 2012, 01:56:51 AM

> JJ and EH are both made by NewSensor?

New Sensor is a distributor. They sell stuff from MANY sources.

The brands you see on tube boxes have little or nothing to do with where they were made, or by who.

Some of their sources are "related"; there is a larger company fronted by Mike Matthews which owns New Sensor and has partnerships in several tube factories and other operations.

seedlings · February 23, 2012, 08:50:12 AM

Quote from: PRR on February 23, 2012, 01:56:51 AM
> JJ and EH are both made by NewSensor?

New Sensor is a distributor. They sell stuff from MANY sources.

The brands you see on tube boxes have little or nothing to do with where they were made, or by who.

Some of their sources are "related"; there is a larger company fronted by Mike Matthews which owns New Sensor and has partnerships in several tube factories and other operations.

Aaah. Probably all information 'they don't want you to know'. These JJs should be in today. If they're bunk I'll send them back to musiciansfriend. Yes, I bought tubes from MF- for the specific purpose that if they don't perform, I'll send them back.

CHAD

danamoose · February 23, 2012, 10:22:36 AM

Quote from: kurtlives on February 22, 2012, 11:19:08 PM
Have you used your DMM and checked for continuity through the circuit and checked it versus the schem?

Also I see your using perf while the layout you linked to is a vero layout. That can be confusing for a first build.

Anyways it looks like your shorting out the red resistor (C1) in the layout. Can you check this.

Hey Chris, long time no see! This is Dana from NY, we met at the Trinity Amp course last year!

I have used the DMM for continuity, looks good as far as I can see. Perf is all I had to work with so I just adapted

can be confusing but its not my first build so Im used to it.
I see from the pics how it can look like that Cap is shorted but I verified (and just re-verified it is not. I was sure to leave it open under it. Thanks for taking a look, I expect to have the new tubes in a few days so I will try it with them when they get here and get back.

seedlings · February 24, 2012, 03:04:16 PM

To complete my OT conversation, the JJ ECC82s arrived. They sound meh. Also found out what was causing my trouble: be sure to put the 1M ground on grid 1

. I had it on the other side of the cap for popping, but not on the grid side.

So... I got that working and back to the old RCA 6FQ7s, which are basically 12AU7 long plates with 6.3V heaters, and sound great. The JJs... Next build will have more voltage.

CHAD

danamoose · February 27, 2012, 11:09:31 AM

Happy to report that it is working and sounds GREAT!

Got the new tubes the EH and the RCA (actually labeled Lowrey Organs) from Larry. I tried the EH through my test amp and still sounded like crap so I was about to tear it down and breadboard it when today I decided to give it one last shot.

I put the Lowrey Organs tube in it and ran it through my 20watt tube amp...OMG it sounds amazing! One major issue I found was that i was testing through my test amp which is a transistor Peavey Rage 158. It made the pedal sound SUPER crunchy and extremely harsh. Once I put it through the actual tube amp it sounded a ton better and the Lowrey organs tube seems to sound the best out of the three I tried. I haven't pulled the voltages with this tube in it but I don't think i am going to bother!

Big thanks to Larry for the tube and to the rest of the guys who offered advice on this threat!

On to the next build.....

seedlings · February 27, 2012, 03:28:45 PM

Quote from: danamoose on February 27, 2012, 11:09:31 AM
Once I put it through the actual tube amp it sounded a ton better

This is super-handy advice for the masses.

CHAD

danamoose · February 27, 2012, 04:36:33 PM

*Update*
Sounds GREAT at 9 volts too!

Is alot more compressed with less head room for sure but very usable still. Less overall boost at 9v also but way more than enough for anything I will ever need to do!
Great day!

Renegadrian · February 27, 2012, 09:03:34 PM

Nice to read those words (sorry I didn't answer, I wasn't too much online those days)
Yeah I have some NOS and a lot of them sound AWESOME (Sylvania and Raytheon are my favs) and some 5963 too.
You can catch some NOS for cheap on evilBay if you're lucky!
I had a recently made EH on my very first valvy but I never liked that much, sounded a little flat to my ears...but it works ok.

danamoose · February 28, 2012, 08:32:34 AM

Thanks for the layout Adriano! The more I play this pedal the more I love it! It sounds like no other pedal I have heard before!

The biggest problem I am having now is deciding what to build next! Absolutely loving working with tubes though so I know it will be another tube pedal.
Im thinking either one of Ricks small amps or Merlins Spark Gap. Im sure both are in my future just which will be first.
:icon_biggrin:Thanks!
-Dana

Finom1 · February 01, 2017, 03:37:47 PM

Does anyone have a working link for the schematic?
Thank you.

rutabaga bob · February 01, 2017, 04:51:35 PM

Do a search for the thread 'tube boost + overdrive'...that's the valvecaster thread.

Edit: it seems some of the early stuff doesn't show up...google 'matsumin valvecaster schematic'. The Beavis Audio version shows up in the results.

Sorry...

Finom1 · February 01, 2017, 05:07:49 PM

Thank you.

cnspedalbuilder · February 02, 2017, 01:53:32 AM

Congratulations. I built that circuit and it is my favorite pedal on the board. I'm using a JJ 12AU7, so I can say they're not all bad. You did a better job than me, though, with the tube placement. Mine is on a socket mounted on the top of the enclosure, so it sticks out quite a bit.

News:

Valvecaster troubles