Rustling noise

If they glow, this is the place to be
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#1 Rustling noise

Post by pre65 »

Hi-my 832 PP amp seems to have developed a "rustling" noise on both channels that is audible on quiet passages of music from my listening position.

I have tried another amp (300b) and i cant hear it with that so should rule out the pre amp.

Thing is apart from the transformer the amp is dual mono so what might be causing it ?
Attachments
832 PP 001.jpg
832 PP 001.jpg (71.01 KiB) Viewed 12346 times
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
Darren
Old Hand
Posts: 659
Joined: Mon May 21, 2007 10:58 pm
Location: N/Wales
Contact:

#2

Post by Darren »

Dirty valve pins, or the socket.

It happens in my phono stage from time to time, I just wiggle the valves till it goes away again.
User avatar
ed
retired
Posts: 5384
Joined: Thu Jun 21, 2007 4:01 pm
Location: yorkshire
Contact:

#3

Post by ed »

its autumn its bound to happen. The poplars, they are mostly to blame.
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#4

Post by pre65 »

Hi-i took out all four valves and de-crudulated the pins and now it dont rustle !

Thanks for the advice.

Went out on a trail ride today on my KTM and it seems that most trees round hear are leafless.

Bear a thought for those poor buggers on the East coast low lying areas tonight.They are predicting similar wind and surge tides to 1953.
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
Darren
Old Hand
Posts: 659
Joined: Mon May 21, 2007 10:58 pm
Location: N/Wales
Contact:

#5

Post by Darren »

Very good Ed....wouldn't want you to think it went a bit high !


The rustling can sometimes be very hard to get rid of Philip, some valve seem to be more troublesome than others.
Lee S
Old Hand
Posts: 664
Joined: Fri Aug 10, 2007 9:39 am
Location: UK

#6

Post by Lee S »

Just to bump this back up to the top.

I have started to get a rustling noise from my LW. I immediately assumed dodgy valve or dirty pins. I swapped the ECC83s over and it made no difference. Still intermittent low level rustling sometimes increasing to a short loud rustle now and again, from the left channel. Hmmmm..... can't be the 2A3 can it? Swapped the 2A3s over left to right and surely enough the rustle followed to the right channel. I have polished the valve pins with some fine wire wool, but it didn't work. It still rustles every now and again. Guess these valves don't last forever.

I was really just wondering what causes this rustling, especially in a larger DHT such as a 2A3? Any ideas?

Time to get some more 2A3s for spares I think!!

Cheers
©2020 Lee
User avatar
Nick
Site Admin
Posts: 15708
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#7

Post by Nick »

I would check the voltages around that 2a3, make sure they are as expected.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
Lee S
Old Hand
Posts: 664
Joined: Fri Aug 10, 2007 9:39 am
Location: UK

#8

Post by Lee S »

Hi Nick.

Just checked voltages and all are as expected and exactly the same on both channels. It's stopped rustling now too. It may start again any time though. It has to be the actual valve doesn't it, if it follows the valve? There is nothing else in the circuit it could be is there? I just put it down to a worn/dodgy 2A3.

Cheers
©2020 Lee
User avatar
andrew Ivimey
Social Sevices have been notified
Posts: 8307
Joined: Mon Jun 11, 2007 8:33 am
Location: Bedford

#9

Post by andrew Ivimey »

When this happened to my 845SE amp I was worried. But there were so many caps in it (Chinese design) although I attributed it to this, I never really found out. The PSU was nasty and it couldn't last... so it didn't.

The most spectakleer evening the rustling ended in what sounded like static/lightning discharge bangs, though there was no light show and the amp continued to be fine except for the rustling, for a couple more months having gone back to rustling only.

I never did find out, so crap leaky cap, crap leaky resistor, crap amp, hm.

In LW you only have three caps in each amp circuit I believe - easy enough to replace the 20mfd on the ecc83? Then you only have the caps on the cathode of the 2A3 - oh and the 100mfd on the ecc83 cathode.

But if its both channels, blame the PSU caps.

Do the voltages as should be add up?
Lee S
Old Hand
Posts: 664
Joined: Fri Aug 10, 2007 9:39 am
Location: UK

#10

Post by Lee S »

Voltages all add up fine Andrew.

Am I missing something here, but if it were a cap or resistor, wouldn't the rustling stay on the suspect channel and NOT follow the valve? I am expecting another couple of 2A3s in the near future anyway, so I guess that will allow me to try a different pair and see if that solves it.

As the voltages are all fine and the rustling is quite low amplitude and inoffensive I am not too worried. I was just wondering what actually causes it. Is it the filaments moving or is it the grid moving or is it electrons bunching up or something? Maybe something to do with the oxide coating? Just curious as to what it is that makes the noise.

PS: just swapped the JJ ECC83s for some old Electro Harmonix 12AX7EHs. Nice!! Better extension than the JJs I think, especially the highs. They have a bit more bite too. Percussion sounds much more realistic. Sound seems wider and deeper too with better separation. Instruments and vocals seem to have more of their own space.

PPS: Rustling back now... for a while.. then gone again....

Cheers
©2020 Lee
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12273
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#11

Post by Dave the bass »

ed wrote:its autumn its bound to happen. The poplars, they are mostly to blame.
Just caught this thread.

Aha! Rush sing about this...."There is unrest in the forest, there is trouble with the Trees"....

I didn't know it was about rustling valve amps.

In America Valve amps get stolen at night by men in chaps (snigger) on horses equipped with lassoo's, they're know as amp rustlers too 'parrently :D

Not a lot of pople know that,

DTB
"The fat bourgeois and his doppelganger"
User avatar
andrew Ivimey
Social Sevices have been notified
Posts: 8307
Joined: Mon Jun 11, 2007 8:33 am
Location: Bedford

#12

Post by andrew Ivimey »

helpful Dave, just not very :D

I have some sovteks too.

sorry Lee, I missed the point that the ruslers follow the valves; qed, its the valves..... fingers crossed.

I found an eBay chap in Japan, 'vintagesounds' I believe, who is selling sovtek monoplates for about £15 each. not bad. IN fact I chalenge anyone to get them cheaper!

good luck!
Lee S
Old Hand
Posts: 664
Joined: Fri Aug 10, 2007 9:39 am
Location: UK

#13

Post by Lee S »

Andrew, the ones that are coming are mono-plate Sovteks too I think. I will have a quad of those. I fancy a pair of the Shuguang 2A3Cs to play with as well. Might get a pair of those for Chrimbo if I can persuade some flush family member to part with £45-ish. I think a few rave about these Chinese 2A3s.

We will see what happens. The LW is sounding abso-bloody-lutely excellent though. So, so musical!! :D

Cheers
©2020 Lee
User avatar
andrew Ivimey
Social Sevices have been notified
Posts: 8307
Joined: Mon Jun 11, 2007 8:33 am
Location: Bedford

#14

Post by andrew Ivimey »

I do not rave about 2A3 Shuaguangs.

I have tried side by side, nine different 2A3s and the shuaguangs kind of 'clipped'.

My faves without doubt are TJ mesh plates, about £55 each but really are a cut above. Oddly/sadly/strangely (because, I really like 2A3s) the shuaguangs were the only ones that started clipping. I tried high volts, low volts and just right volts.

Interesting ones are the enormous JJs (bigger than your average 300b) which are on the shelf waiting and will have to go in the reborn LW, just because they look so cocky.
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12273
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#15

Post by Dave the bass »

andrew Ivimey wrote:
Interesting ones are the enormous ....(bigger than your average ......) which are ...waiting and will have to go .......... because they look so cocky.
MATRON!
Image
He's at it again.

Sorry couldn't resist a bit of editing :D

DTB
"The fat bourgeois and his doppelganger"
Post Reply