Need help with a tube amp issue. " Fixed"

Dennis Brown · From: Gowen, Mi. USA

I bought a Traynor ycv50 blue, two channel tube amp.
Here is the issue. when I switch from the dirty channel to the clean, it takes nearly a full minute before the clean channel comes alive.
I just got this amp today so, I don't know the previous history.
It sounds good after the clean channel snaps and eventually comes alive. Tubes?

###### Problem was fixed. It was a relay ######
Thank you all for your help.

Steve Sycamore · From: Sweden

Very likely so. I have a set of vintage power tubes that strangely extend the attack time of notes into the seconds range, at least until they're fully warmed up and broken in. That effect is exaggerated between the high and low gain channels.

Jack Stoner · From: Kansas City, MO

I don't think a bad tube would cause that. It sounds like the clean channel tube is being turned on or off and it takes time for the tube to "power on". It would be different if this is the case but what it sounds like.

Dennis Brown · From: Gowen, Mi. USA

Jack, that's about how it reacts. The clean side, doesn't even turn on untill I hit the channel select button. Thats a bummer waiting for the tube to warm up. Any idea why this would happen?

Jack Stoner · From: Kansas City, MO

Most of the "modern" guitar players want the overdrive and rarely use clean. Since the clean side isn't always used powering it on only when needed would save the tube. This is a "far fetched" theory but only thing I can think of.

Benjamin Davidson · Posted 19 Jul 2019 5:05 am

Do you have any sound through the normal channel during that pause, or is it just silence? Does the amp do the same thing switching between clean to dirty?

I'm looking at the service manual, and dont see anything where the tube is powered off when not in use. There is a relay that controls switching channels (common method now to avoid popping. That may not be your issue though.

Further this amp isnt an all tube design - the reverb, boost, and effects loops circuits are solid state.
_________________
Justice Pro-Lite (9p9k) 10 String D13th Universal Tuning

Brian Hollands · From: Geneva, FL USA

Their schematic is too modern for me to read well but the tube heaters are always on so there is no warm up time between channels. Looks like this amp uses relays in the channel switching so I'd guess a bad relay (K1 on the schematic I think) would be the more likely culprit
_________________
'81 Sho-bud LDG, 2 EMCI's

ajm · From: Los Angeles

Does it do this when you first power it up?
Or has the amp been on for a few minutes?

When you first power the amp up and after warm up, does it default to the clean, or dirty, channel?

When this happens, if you cycle the footswitch a few times does it then work like it should?

Is there a way to select channels from the front panel WITHOUT the footswitch plugged in? (I looked, and yes there is.)
Unplug the footswitch and try it.
Does it work now?
If not, what about if you press it on/off a few times?

Just as a totally dumb flock shooting swinging wildly suggestion:
Try cleaning the switches in the footswitch.
Clean the jack for the footswitch in the amp.
And also clean the front panel channel select button.
(This may or may not be the problem, depending upon the answers to some of the previous questions.)

Jack Stoner · From: Kansas City, MO

Looking at the schematics, the filament power is applied to all the tubes, so my original theory is out.

There are a couple of engineering updates (jumper wires) that are installed to update the board. They don't say what they are for but I would check or have it checked (and installed) if not already installed.

There could also be a flakey capacitor causing the problem.

Maybe why the seller sold it???

Manual and schematics:
http://traynoramps.com/downloads/servman/sm_ycv50blue.pdf?v=1

Dennis Brown · From: Gowen, Mi. USA

I appreciate all the replies. This is going on without a footswitch hooked up. I'm switching from the panel. It happens "when ever" I switch from the dirty side to the clean. Hot or cold.
It does not happen going clean to dirty. This morning the clean side didn't want to come on at all, I slapped the top of the amp it came on. I guess I'll take it to the tube doc.
Thanks again.

Michael Butler · From: California, USA

just as a quick easy test--pull each tube partially out and reset it a few times. if that doesn't work, try swapping the preamp tubes one at a time and then the power tubes. make sure the amp is off and the tubes are not hot enough to burn you, so you may want to use a towel.

good luck.

play music!
_________________
please see my Snakeskin's Virtual Music Museum below.

http://muscmp.wordpress.com/

Brett Lanier · From: Madison, TN

Since you say you just got it, I'd look into returning it if that's possible. New Traynor amps are nothing like the old ones. I'm a tube amp guy for the most part, but still I think a classic solid state peavey steel amp like a nashville or session 400 will sound better than a new Traynor.

Dennis Brown · From: Gowen, Mi. USA

Michael, thanks, I tried your suggestion, no luck.

Brett, thanks, The Traynor is for my lap steels. I use a NV400 for pedal steel. The Traynor is a early 2000's.

Jim Kennedy · From: Brentwood California, USA

If the relays are plugg in swap them if they are the same. I was an old school radio technician in the navy in the mid 70's. All tube Korean war vintage land based 40kw transmitters. Lots of relays that caused all kinds of problems. Swapping common parts was one way to quickly trouble shoot this 50's vintage equipment.
_________________
ShoBud Pro 1, 75 Tele, 85 Yamaha SA 2000, Fender Cybertwin,

Benjamin Davidson · Posted 19 Jul 2019 5:42 pm **Re: amp issue**

Dennis Brown · From: Gowen, Mi. USA

I agree Benjamin. Thanks all.

Michael Brebes · From: Northridge CA

Looking at the schematic the only real culprit for your problem would be relay K1. Nothing else could or would react that way.
_________________
Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso

Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100

ajm · From: Los Angeles

If the hunches of others who have posted are correct, if it's K1 it could be the relay itself, or it could be a bad solder connection to the PCB.

It looks like the solder traces are on the underside of the board and are not easy to get at.
From what little I have been able to dig up on the internet, any ICs and relays and similar components are solder directly to the board and do not use sockets.

Good luck, and let us know what the final fix is.

Dennis Brown · From: Gowen, Mi. USA

Thanks Michael and Ajm. I will let you know the outcome.

Steve Sycamore · From: Sweden

Some other possible problems:

Bad connection across R17.
Bad connection across R18. There are 300 volts on one side. Don't come near this unless you're a tech!!!

Since there is some signal coming C24, R21, R22 and R23 are less suspect. Or is there no sound in channel 1?

Do the tone controls have an effect when the sound is low?
Do the Bright switch and Volume control have an effect?

Forum Index > Electronics		Next oldest topic :: Next newest topic