Hi Dan, I had the same thing happen, new unit (musicians friend) sound got thin, mild pop and left tube super hot started smoking so turned it off asap. Tubes seems to be the thing?
Thanks
Hi Jef,
It could be bias related but yes, it could also be what you mentioned.
Can you post a high-resolution image of the PS-100 without the lid? Fit it fully in the frame, we need to be able to see the details. Just one image is fine. This will help us diagnose the issue further.
Hi Dan, any thoughts on the pic?
Hi Jef,
There are no obvious signs of damage, etc.
There are a few things I want to check with you, but first please give me an update. How is the unit behaving now? If you turn it on, does the left tube still go red?
Please excuse any repetition here, but I need to rule out possibilities other than tubes before continuing. Would you please simplify your setup to be bare minimum. No FX. No Line In. Just you amp to AMP IN and your speaker to SPKR OUT.
Then please follow the NO SOUND and RUNNING TO HOT steps in the checklist. It should take around 10 minutes to complete. The steps might seem silly, you will be surprised how many times they work!
It is surprising. Did the amp in and speaker out, it worked. Then added a speaker in series so switched from 8 to 16ohm, it worked. Then added a delay and a reverb pedal in the loop exactly like my initial setup and it’s been working for the past couple of days.
Sounds great and the tubes seem to have mellow even glow.
I don’t get it but thanks
Hi Jef,
OK, let’s monitor it then over the next few weeks. Please come back here if anything changes!
Ok, having just posted that I played for about 30 min heard that pop again but tubes looked normal and sounded fine. Played another 30min or so and without a pop sound went thin and half volume, this time with the right tube very hot looking. Turned it off for 10 min and it worked fine again. Some strange break in.
If it helps I’ve been using a 20watt black cat with volume and master on 5, the two speakers are connected with a radial cablink. Room volume slightly louder than a strummed dreadnought.
Thanks
Hi Jef,
OK intermittent signal popping and crackling can sometimes occur with 6550s we have seen that before, particularly with Sovteks, and it normally clears itself up.
However, the thinning of the sound and the very hot-looking tube are signs the tube is going bad and we should sort that out. I mean, it could be a biasing issue, but probably is not.
Before we continue, where are you located (approx.) and buy the unit from? The serial number would be useful.
Hi Dan,
I’m located in Hawaii, unit came from musiciansfriend. PH ID244143
I find it interesting that it was first the left tube and then the right tube. Cause they work as a pair?
Thanks
Hi Jef,
We will send you out a replacement set, as it seems they are both failing. If it were a bias issue, it would always be the same tube running hot.
Please fill out this online form. It will ask you to post a picture of the inside of your PS-100. This will help us get the best set sent out to you.
Please note that they will ship next week, as a few members of the team are off sick at the moment.
Thanks Dan, appreciate it.
Pic is in the 3rd post