Discovering my guitar amp
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Posted on Oct 08, 2009 02:14 pm
Quincysan
http://www.unitedmusicians.info
Contributor Since: Nov 11, 2007
So I played around with the JJ ECC83S 12ax7 pre-amp tube, I like it, but from how Noize describes the Tung Sol 12ax7 I might like that more, so I ordered that. As an added bonus, when I was replacing my tubes I found what appears to be an additonal 12ax7 socket located right below what I had formerly perceived to be a broken built in tremolo effect pot.
Do some of these old tremolo effects use 12ax7 tubes? I can only imagine that's what the additional tube is for...I imagine the JJ ECC83S will suffice for the tremolo?
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Oct 08, 2009 02:30 pm Sad to say that it depends on the company.
Some used the 12AX7, others used the 12AU7, or even the 12AT7.
Ampeg even used the 12DW7 as part of the effect loop.
Do you have an old 12AX, and and AU any where? From either an old or even new amp?
If you have them both, try both in there. You will know which one is the right one after that. One you will just barely hear. The right one will have the Trem volume at the right spot.
Oct 08, 2009 02:40 pm By the way. If you ever need to know tube specs, or even what substitute tube number that you need?
There is a great program out there from Duncan amps.
www.duncanamps.com/tdslpe/download.html
Download the Personal edition. Or the one with the installer icon. It's a program that I can't live without when it comes to tubes.
Quincysanhttp://www.unitedmusicians.infoContributor
Since: Nov 11, 2007
Oct 08, 2009 02:54 pm Oh I'm not sure that's a "sad to say" situation! I'm very interested in learning what my amp is...so if I have to go through a little trial and error to find the right tube...perhaps that will put me closer to finding out what this thing is.
Thanks for the tip. I have the old 12ax7a that was originally in the amp. Not sure if it's totally fried or not but when I tried to plug it in it wouldn't fit well, but I'm thinking the pins on the old tube were a little bent.
I'll have to find a local electronics guy with a stock of tubes to trial and error my way to tremolo success.
Quincysanhttp://www.unitedmusicians.infoContributor
Since: Nov 11, 2007
Oct 08, 2009 02:54 pm will download. Thanks.
Oct 08, 2009 03:17 pm To give you a heads up on how the program works, at the top, next to file. You will see search.
Click search, then "By Designator"
Type in the number of your tube in the field provided.
Then, on the main window. You will see a tab marked "Substitutes"
This will tell you all of the tubes that are close, or the same as the tube that you are looking for. You want to look for all of the ones that are "Close or Identical"
Quincysanhttp://www.unitedmusicians.infoContributor
Since: Nov 11, 2007
Oct 08, 2009 08:47 pm Oh yeah I was playing around with it...SO MANY SUBSTITUTES! I actually sent it to a couple friends who might benefit from it as well, thanks again. Really cool program.
Noize2uCzar of MidiAdministrator
Since: Apr 04, 2002
Oct 08, 2009 11:31 pm On the Tung Sol tubes. We just dropped a set into an older 50 watt Mashall and it completely changed the character of the amp. It almost has a 5150 kind of feel to it now. And you know how a Mashall has a tendency to get extremely mushy if you put too much bottom on it. We had it plugged into a Custom Mills Acoutsic's 4x12 cab which has a huge bottom end to it. And this thing had such a cool sounding bottom. We AB'd it with 2 other similar Marshall heads 1 with Sovtek and 1 with pretty much stock tubes. The Tung Sol was so much smoother all the way through turning the gain up. And it never got that muddy sounding low end when rolling a bit more bass onto it.
I am now completely sold on those tubes from this. That and a decent amp head to start with.
Quincysanhttp://www.unitedmusicians.infoContributor
Since: Nov 11, 2007
Oct 10, 2009 02:12 pm Just replaced the JJ ECC804S with the Tung Sol version. Appreciably different tone. They are both fantastic. I'm going to have to play around to figure out which one I like more...though I'm pretty sure the Tung Sol is giving me a little more volume for playing clean tones before it starts to break up...I have this fantastic $30 Yngwie Malmsteem OD pedal to get it dirtier when I need it, thanks for the tube recommendation. When I'm playing from the single coil by the neck I can get a great crystal clean tone but when I start wailing away it breaks up in the best kind of way...oh buddy. Strange, but I think the most affected part of my tone from the new tube is through the single coil in the middle...much more character than before...sorta...quacky...
So...the ECC804S doesn't seem to fit the tremolo tube socket...but the pin out configuration is the same. It almost seems like the little circle of pins is just a little too wide to fit into the socket. Are there sockets that look identical to the kind that the ECC804S uses but just a tiny bit smaller...or should I keep trying to fit the thing in there? Maybe one of the tubes that Rob mentioned?
Oct 10, 2009 08:47 pm Hummmm, It would be very rare for your amp to have this.
But, some amps do use 6V tubes for part of the pre.
Now I am not saying that this tube slot is a 6V. But I am saying that it is not out of the realm of possibilities.
Do you know how to use a multimeter?
If you do, there is a way of finding out weather or not if it's a 6V, or a 12V tube.
Use the program that I gave you the link to. Look up a 6CL6 tube. On the Pin Out tab, it will list 2 "h" pins on there. I believe that it's pins 4 and 5.
Measure the voltage between the pins and ground. (The red lead on the pin, the other on the amp chassis.) And see if you get around 6 volts, or around 12 volts.
If it is the 6 volt version, then the 6CL6 is a good starting place for finding the right tube that goes in there.
If it's 12V, then I need you to take a picture of the tube slot. So we can try to figure out why the tube won't fit.
Quincysanhttp://www.unitedmusicians.infoContributor
Since: Nov 11, 2007
Oct 12, 2009 12:01 am Tomorrow morning I'll go up to the Geek Squad I used to work at and demand they let me borrow their multimeter, bahaha.
Here's hoping I don't get fried in the process...I never did replace the 2 prong power plug...
Noize2uCzar of MidiAdministrator
Since: Apr 04, 2002
Oct 12, 2009 12:48 am You gotta do something with that plug.
Quincysanhttp://www.unitedmusicians.infoContributor
Since: Nov 11, 2007
Oct 12, 2009 01:20 am @Noize: I know...it's only 1 6L6 and one ECC804S...does that make it less dangerous? Either way it needs to be resolved. Will I be blown to kingdom come if I try a multimeter on it tomorrow morning? I've used multi-meters quite a bit and I know what goes where and why.
Regarding the tremolo socket though. The 12ax7a/ECC804S uses a 9 pin, and the tremolo socket is definitely a little smaller and uses a 7 pin tube...
hmmmm, interested to see what the multimeter says...but first I'll need to know where to stick the multimeter.
Noize2uCzar of MidiAdministrator
Since: Apr 04, 2002
Oct 12, 2009 01:33 pm Rob will know were to stick the meter I'm sure. I don't remember hardly any of that stuff from not using it for so many years.
But no, you won't get blown up by the 2 prong.
TadpuiI am not a crook's headMember
Since: Mar 14, 2003
Oct 12, 2009 02:37 pm But do remember one thing that applies to ALL tube amplifiers:
Tube amplification relies on the use of some very high-capacity capacitors that can store enough voltage and release it at a high enough current to really injure or even kill you. Those capacitors can store voltage for a long time after the amp has been turned off or even unplugged. If you touch the wrong spot and short-circuit the wrong wires, you can bleed those capacitors and get a hell of a jolt of electricity sent through you. Depending on which of your body parts are grounded, it can send that jolt through your heart, which you can imagine isn't a good thing.
Just be very careful when poking around inside a tube amplifier of any sort, even a low-wattage one. It's no joke that they can be lethal.
Oct 12, 2009 11:50 pm When you get the meter, I don't want you to take anything apart!!!!!!
You can get to the pins right from the connector under the amp.
And make sure that your hands stay on the insulated portion of the probes.
The Black will go on the metal of the amp itself, and the Red will go to pin 4, then pin 5.
For the heater portion of the power, it's not heavily regulated. Meaning that it may have some AC current to it. It's a heater, so who really cares.
Just set the meter to DC, and check to see what the voltage is close to. 6, or 12.
And then we can start to find out what tube should be there.
pjkPrince CZAR-mingMember
Since: Apr 08, 2004
Oct 13, 2009 09:35 am There's the rub, if your not sure which pin is 4/5 or other heater pins (which probably wont be if it's a 7 pin socket) then you may not know if your touching b+ or whatnot. And B+ is tied into the filter caps, therefore, you could be touching large amounts of voltage, waiting for a ground.
Like mentioned above, tube amps are not something to take lightly. they can kill if you touch the wrong spot without proper preparation.
If you're going to remove the 2 prong and put on a 3 prong grounded plug, then the amp needs to come out of it's shell, and you're exposed to lethal voltages, even when unplugged. I've grounded out my first amp into my arm, and it was quite exciting (hmmm, i taste pennies). Luckily it was lower voltage (~240) so I wasn't risking getting 500v into my body. And, I grounded from my hand to my arm on the metal frame, so it didn't go any further (thankfully).
If you're inspired, reading up on how to drain the caps would remove most of the danger. Involves 2 alligator clips, a resistor, and knowledge of which places to attach the clips to. This will leave you with a nice empty filter cap array.
hth.
Quincysanhttp://www.unitedmusicians.infoContributor
Since: Nov 11, 2007
Oct 13, 2009 02:31 pm Here's my assumption...
BeerHunterwww.TheLondonProject.caMember
Since: Feb 07, 2005
Oct 13, 2009 03:10 pm You will be fine... just hold the hand of the drummer ;) j/k - take care of yourself
Noize2uCzar of MidiAdministrator
Since: Apr 04, 2002
Oct 13, 2009 08:45 pm Nice drawing by the way Quincy.
Quincysanhttp://www.unitedmusicians.infoContributor
Since: Nov 11, 2007
Oct 14, 2009 03:27 pm Haha, Photoshop who? msPaint is King.
