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Blew something in my amp with the HD500 in the effects loop...
by mtnbkr123 on 2012-01-30 14:09:52

Last night after playing for a while at low volume with my HD500 in my effects loop (4CM) of my Traynor YCV40 tube amp, I heard 2 or 3 loud pops followed by the lovely stench of electrical smoke from my amp. Strangely, everything seems to be working fine. I'm bringing it into the shop after work. They think I blew some solid state component in the effects loop.

Any ideas what it could be?

Any ideas what caused it?

Better yet, any ideas how I can prevent it from happening again?

Mike



Re: Blew something in my amp with the HD500 in the effects loop...
by mtnbkr123 on 2012-01-30 16:44:23

Among other things I fried the standby circuitry. It still slams hard but without any standby. It's now in at the shop for a week and a half (minimum). Great.

Guess I'll find out in due course whether it was related to the HD500 having been in my effects loop at the time. Not dissin the HD - even if it's related, I very possibly could have had something screwed up connection-wise.

In any event (in case you're wondering what on earth this may have to do with the HD), I'll post any screw ups I might have done with he 4CM to maybe prevent someone else doing the same thing. I had a full on smoking amp rock show going on in my living room at 11 pm on an otherwise pretty quiet Sunday night.



Re: Blew something in my amp with the HD500 in the effects loop...
by jimsreynolds on 2012-01-30 17:01:47

It seems unlikely that the HD was the cause of the loop biting the dust.  Having said that:   it would be interesting to hear what comes back from the repair guy as to their suspected cause too.

Sorry mate ... sucks!



Re: Blew something in my amp with the HD500 in the effects loop...
by toneman2121 on 2012-01-30 18:29:29

sometimes electronics just die. but i would sure like to hear the end of the story.



Re: Blew something in my amp with the HD500 in the effects loop...
by adamf on 2012-01-31 02:47:05

Just a thought on the topic....using the 4CM if you were to put say a compessor or high gain effect  in the amp section and totally boost  it... I'd imagine the power tubes would be at risk.



Re: Blew something in my amp with the HD500 in the effects loop...
by jimsreynolds on 2012-01-31 03:47:38

There are amp schematics here if your repair guys need them -->  https://docs.google.com/viewer?a=v&q=cache:SdXt-TLDTioJ:www.traynoramps.com/downloads/servman/smycv40.pdf+Traynor+YCV40+manual&hl=en&gl=uk&pid=bl&srcid=ADGEESjcgAssMooiIuH8QvPj79OpsoWQa3z-w9BV8OsFJS_CTy8lPzsk7OO3bMNz8m80m7DlK8AQYpiNCJhTv_H-iOS9Z8dfHvzCKeaKTipNWa1EazAjXtfGCqvDMW4MUXUdd1YynGJX&sig=AHIEtbSmK4MTvqjzlQiC4BSkiuBXSaY3bw

Apparently they can be downloaded from the Trayor site as a PDF but that seems to be down.  Hence the google link.

It looks like the tubes in the amp are used for pre-amp, phase splitter and power tubes only so yeah, the loop is all solid state.

The manual describes the loop send as -10dBV (standard instrument level) but describes the return as EFX/Line.  The 'line' bit suggests that a line level return should be fine (+4dBu).


On adamf's point.  I have been digging around too cause I have been interested to see whether jacking a line-level connection into a power amp is always 'safe'.  So far I have not seen any evidence that would suggest that running a line level (+4dBu) into an instrument level loop/power amp return can cause any damage other than creating unwanted distortion.  This is what I would expect too.   The +4dBu is about 3-4 times the voltage of -10dBV but you are still talking in the range from 0-2V which is very low.

From a power amp perspective:  using 4CM is identical to using a 'Stack/Combo Power Amp' type connection with the POD jacking straight into the power amp so 4CM is not inherently any worse than this.

I guess it is not beyond the realms of possibility that Jacking a line level connection into an instrument level loop return might fry a very sensitive component or circuit but in practice people do it all the time, not just here but in recording situations too where people constantly inadvertently mismatch the levels.  I just don't see that it can be a major issue.   You will wreck your tone but I think it is highly unlikely that you will wreck your gear.



Re: Blew something in my amp with the HD500 in the effects loop...
by Detch on 2012-01-31 08:10:42

I think it was your POD.

I had those terrible pops or clicks on my POD HD desctop. I don't know why i happens. I had no compression in my patch. only amp.



Re: Blew something in my amp with the HD500 in the effects loop...
by mtnbkr123 on 2012-01-31 18:17:13

So...I talked to Guy at Traynor for an hour today. He suggested that I pick my amp up from the shop, grab some non-Russian power tubes (6L6s) and not worry about the standby. The popping apparently was a power tube shorting which fried something having to do with the standby circuit. There are 3 small components in the power supply that need replacing ($9). I'll bring it back in when I go on a trip or something so that I won't miss it when it's gone. A week and a half is a loooooong time. I'll also get them to order the 3 components in the meantime so I won't be waiting for them. The tech at the shop was not very confidence inspiring.

No idea if any of that is right or wrong, but I picked up a set of Groove Tubes and my amp and I'll be heading home from work pretty soon to check things out. I guess I'll find out how much I relied on the standby mode now that it's gone.  He said to plug the amp in for 4 days straight - if the new tubes survive the first 100 hours, there's a 96% chance they will last a long time.

Looks like this had nothing to do with the HD.



Re: Blew something in my amp with the HD500 in the effects loop...
by jimsreynolds on 2012-01-31 23:50:57

The Traynor guy sounds much more plausible.  There are notes at the end of the service manual link I posted showing some kind of mod relating to the standby switch so it sounds like there is a known issue.

Sounds promising.



Re: Blew something in my amp with the HD500 in the effects loop...
by adamf on 2013-02-04 16:53:26

Glad to hear it..It's always nice to hear its not going to be really costly or terminal.  Good luck



Re: Blew something in my amp with the HD500 in the effects loop...
by joel_brown on 2013-02-05 07:07:33

I would strongly recommend getting the Standby repaired.  It's a good idea to warm up tubes before sending juice to them.  Otherwise it'll cost you in the long run with buying tubes more frequently.  Groove tubes can be really nice depending on which ones you buy.  I've found that Groove Tubes LS is the best, M is good, and don't buy R.



Re: Blew something in my amp with the HD500 in the effects loop...
by jimsreynolds on 2013-02-05 07:44:32

Just bear in mind guys that this thread died in Feb 2012 !



Re: Blew something in my amp with the HD500 in the effects loop...
by adamf on 2013-02-05 08:55:27

Oooops ....well at least it got some action going



Re: Blew something in my amp with the HD500 in the effects loop...
by joel_brown on 2013-02-05 17:39:03

Wow, didn't even notice the year.




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