Syn-50: noise when turning-off

[wahlsn]

Hi all,

I am hoping to get any advice from someone owning a Syn-50 as well.

In short:
Could someone please verify whether the same behavior is seen on your device as well:
- turn on the amp fully
- turn in standby for 3-5s then power off
- is there any noise coming from the cab after a few seconds (check with recording later this post)?
This is highly appreciated!

Long version:
Recently, I purchased this amp and I am still under the 30-day-return period.

I just noticed when I turn it to standby and then after ~5-10s to off, there is a weired chromatic-falling squeal sound, like a capacitor slowing discharging, after a few seconds.

I did not realize this at first. I have nailed it down to the following setup:
- no guitar connected to the input.
- only 1 speaker cab connected (impedance is set correctly, also other cabs show the same behavior also using different cable)
- happens only, once the amp was turned on fully (not just standby -> then off again)
- 2 pre-amps installed (SLO and 6505), they both do not behave like this if I used them with my Syn-1 and a PS2a before.
- The box and speaker cable is working fine with my other tube head

The only way to get rid of this sound is to wait longer (~30s) after standby before I turn off the amp completely.
This really makes me think there are some capacitors discharging.

Question: is this normal for this amp? I did not have this on any other tube amp before.

I reached out to my dealer first and they could not reproduce it on an Syn-30. However, as far as I understood the power amp design is different to the Syn-50, so it might behave differently.

I also reached out to Synergy directly more than a week ago but did not get any reply yet.

Here, a recording of the sound:


In the .mp3 file you can hear the amp
- operating (some noise in the background)
- first click is the standby (noise disappears)
- second click is power off (then the squealing sound happens)

The amp is great otherwise. I just want to make sure there are no defects that will cause an early fail of the amp due to this behavior.
Searching various forums about this behavior in different amps was not that much successful. I could only find a few references and the answer was everything from "replaced the caps, then everything was fine" to "expected behavior and good sign that caps still hold charge" and between.

Thanks for your help!
Simeon

 

[alboz28]

I have a SYN50 - That is compleyely normal - it is dischraging the capacitors when powering off - it is a feature

Enjoy

 

[wahlsn]

Thanks a lot, alboz28, for your reply! This is a great relief. I thought/hoped something like this but got confused when my dealer told me that he cannot reproduce this. But as I wrote, I strongly belief, they tried the Syn-30 as this is currently the only Synergy head they have left in stock.

Best,
Simeon

 

[BurnBackTime]

Thanks a lot, alboz28, for your reply! This is a great relief. I thought/hoped something like this but got confused when my dealer told me that he cannot reproduce this. But as I wrote, I strongly belief, they tried the Syn-30 as this is currently the only Synergy head they have left in stock.

Best,
Simeon

I was wondering the same thing when I first got my Syn-50. I contacted Synergy and they said it was completely normal as alboz28 stated. I just leave it on standby for 30 seconds or so before powering it down and it won't do it. Worried me for sure at first!

 

[wahlsn]

I was wondering the same thing when I first got my Syn-50. I contacted Synergy and they said it was completely normal as alboz28 stated. I just leave it on standby for 30 seconds or so before powering it down and it won't do it. Worried me for sure at first!

Thanks, I will do the same now!
Really enjoy the amp :⁠-⁠)