• Disclaimer: This Vendor's Forum is a paid-for commercial area. Unlike the rest of diyAudio, the Vendor has complete control of what may or may not be posted in this forum. If you wish to discuss technical matters outside the bounds of what is permitted by the Vendor, please use the non-commercial areas of diyAudio to do so.

SSE hissing problem.

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi all,

I'm hoping you can help. My SSE hisses in use. Its intermittent but frequent and isn't exclusive to one channel. I it sound like radio noiee between stations or between tracks on a record.i've swapped all the tubes to no avail, used different sources, cables but again, no change.

Going up and down in volume appears to instigate it. It can even occur quite reliably at certain points in the volumes position so I changed the volume pot but again, no change.

Help!
 
Hi, thanks for the suggestions.

I've just visually inspected all the Pcb components for obvious defects but found none. I've tightened all the tube sockets to give a better connection but that also made no difference.

I'll fire up the soldering irion tomorrow to reflow the solder joints but, failing that how does one identify a faulty resistor or is it best to simply replace all of them?
 
The same as this one.

SSE_grounding_1.jpg


I've star grounded everything to one point then grounded that to the iec socket.
Its not a humming noise though, its the crackly hissing noise between tracks on a record. Very odd.
 
Hissing that changes can be a faulty tube/driver tube most likely. Try a few more 12AT7 - preferable old stock. Check your wires going from the input jack to the volume pot and solder joints on the volume pot. I twist my signal wires if not using shielded cable and be SURE the signal wires are as far away from your AC jack and AC wires going to the power transformer. Basically isolate those signal wires as best you can. Post a pic of underside maybe there's something glaring at you and another set of eyes can sometimes be a good thing.

Notice how on George's diagram all the signal wires are off to one side of the chassis away from most all the other wires. There's a reason for that not just to make the diagram easy to follow.

Cheers,
Bob
 
I've tried multiple tubes which has made no difference.

I've kept the speaker terminals and input terminals away from the power supply wiring and is actually compartmentalised.

The input wiring is shielded, grounded and twisted.

The speaker wiring for the left channel is very short and goes no where near any power cables (it is only the left side that is hissing on and off, the right is fine and clean).

All components have been checked and, are the same part numbers specified by George and obtained from Mouser.

This noise hasn't been there from the start. I've had 6 months of clean sound and the on/off hissing has only been present since late last year. I've only just got around to doing something about it.
 
I should mention, turning the volume up and down excites the hissing and, if you turn the amp off with music playing the volume slowly declines as the power reduces which is normal but the hissing stops immediately when you throw the switch to off so you get a few seconds of clear sound.
 
Frustrating.

I purchased two new ccs's but ran into trouble. I replaced the left channel ccs's and it didn't work so I then replaced that one again but the second ccs's failed to work too. I observed all the handling protocol but after fitting there wasn't even a crackle!!
I've refitted the original old ccs's and we're back to square one again. What are the chances of receiving two bad ccs's?
 
Frustrating.

I purchased two new ccs's but ran into trouble. I replaced the left channel ccs's and it didn't work so I then replaced that one again but the second ccs's failed to work too. I observed all the handling protocol but after fitting there wasn't even a crackle!!
I've refitted the original old ccs's and we're back to square one again. What are the chances of receiving two bad ccs's?

Where are you sourcing your CCS ICs?? Which ones are they?? Pretty unlikely you get 2 bad ones. Maybe your solder joints are suspect or you have them mounted backward. I did that first time but never powered on, I just had a feeling it wasn't right so I slept on it woke up fresh and reversed them.. When I purchase ICs I always buy an extra set for the Murphy's Law thing.

You can test those current regulators with your DMM, unlikely they are both bad, I'd be looking at your wiring. Why dont you take a picture of how they are on the board and post here.

Cheers,
Bob
 
It turns out that the ccs's I bought were copies and not genuine IXYS items. I verified correct fitment and had others check I fitted them in the correct orientation too just incase I was losing it.

I've ordered replacements from digikey so hopefully I'll have them soon.

The noise has improved since I've been playing with the ccs. Likely it wasn't getting a good enough contact with its heatsink and allowing it to adequately dissipate heat.
 
It turns out that the ccs's I bought were copies and not genuine IXYS items. I verified correct fitment and had others check I fitted them in the correct orientation too just incase I was losing it.

I've ordered replacements from digikey so hopefully I'll have them soon.

The noise has improved since I've been playing with the ccs. Likely it wasn't getting a good enough contact with its heatsink and allowing it to adequately dissipate heat.

Did you order the heat sink kit as well. Those chips wont be happy unless they get some heat dissipation. I think they will just cut off at the specified heat tolerance. With chips I don't cut corners just get the originals from a trusted source (Digikey = trusted) and you will be fine. There's too much crap out there to wade thru and find the goodn's.

Good luck there.
Cheers,
Bob
 
I used the ones advised by George, they've been on there since day one. They're well exposed, the amp chassis has no plate under neath and there's an adequate air gap for air to be drawn in from under the amp. The holes around the tubes are a good size too so it should draw some air up and over the pcb/ccs via convection.

Oddly the other channel was making the occasional bit of noise today as well. Oh joy.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.