help with noise at startup volume turned down

[Hornet900]

Hello 

I installed the speedball upgrade yesterday amp was working fine for 24h. ( well maybe I didn't notice problem at first ?   

Today i went to change tubes and when i started the amp up I had a noise with the volume turned right down,  .. when I raise the volume the noise goes away and also the noise goes away after a few mins when the amps warmed up 

(noise is only at startup with the volume turned right down for a few mins)

Its the same noise I hear when I  pull the headphone jack half way out the headphone socket,/ and seems to be louder in the left channel.

This is with no source plugged into the amp,

Edit:

been investigating a little and the noise can sometimes stop when I touch the headphone cable  (only sometimes this will stop it  when  its warming up a little more.
I had a prod inside and when i Moved the ground wire (long black wire)which connects  headphone jack to Term 12L  the noise gets louder never quieter.  This cable can make it alot worse when moving it. (i reheated these joints but never fixed it)


I've not changed anything and it happens with all my tubes now,  amp was perfect before

[Paul Birkeland]

If this only occurs during warmup, it can be considered normal and not worth troubleshooting. 

[Hornet900]

Hi 

I tried my other tube today and I get the same noise even if the amps fully warmed up never goes away....  (volume at 0% to about 5mm turn.... left channel loud noise
slight noise in the right 

And with the tungsol tube the noise is always there till the amps really warmed up.... turning the volume like the stock tube it doesn't go away.... I have to wait 5 mins before plugging in the headphones and never turn  volume down .

If I turn volume up to max it will go quiet tho with this tung sol ... stock tube noise goes away playing with the volume and it goes  completely quiet at %0 volume when amps warmed up.

Touching the headphone cable makes it go quieter while its warming up and also the headphone socket.

Its a tungsol 5998 and worked fine without the speedball,  Shame as I really like this tube with the  speedball  sounds amazing

Does those little pcb boards A and B  run the different channels? maybe is could be something on those?  or could I of damaged it pushing down the caps when installing the speedball
I had little bit of trouble getting those down.

 I'm so unhappy    I love the sound but this noise is driving me crazy   

Hope I made some sense I find It hard to explain using a keyboard I'm sorry

[Doc B.]

Touching the headphone cable makes it go quieter while its warming up and also the headphone socket.

Well, that looks like a hint for you. Sounds like a bad ground connection.

[Hornet900]

Just been listerning to some music

I can turn the volume down while the musics playing but not to the last 5mm of travel to  fully closed volume,   noise in the last 5mm close volume.

Could it be a faulty volume control  that the speedball highlighted?

Also I done a ground check working in the order it says from ground check sticky post and I get a reading of  000.0  with volume pots  same  rca's but from the headphone jack onwards  it starts to go up from 000.5 headphone jack up to about 000.8 to last place.
When i was  measuring the caps for 0  when  installed the speedball I could never get a solid reading its was always moving up and down ( is this right??

I didn't check these grounds from the sticky thread see below

Quote from sticky
"Other points that should be a solid ground are pin 8 of the large tube, pin 4 and 5 of the small tube, T8, T11, T14, T16, T17, T20, T22 and the ground post on the IEC power connector, the one with the bare wire to the chassis."

[Doc B.]

Try exercising the pot by running it up and down through its full range several times and see if that changes the noise.

[Hornet900]

Hi Doc

tried it a few times didn't work    The volume has lossen up alot I think not quite a stiff but maybe its just worn in a little I do move it about alot , play my music very loud I do 

Btw the amp sounds amazing with the speedball and tungsol , I was very happy with the stock crack and prefered the stock tubes with stock amp, But now with the tongsol it sounds unbelievable!

I will look into it more later just listening to some music for a wee while then going to  bed  ,,,

thank you!

[Hornet900]

Hello

Good and bad news
I removed the 2 little green pcb boards today to reroute some of the wires under them as one of the wires was tight up behind the nylon stand offs  and It seems now  I have no noise trouble!
it goes completely silent after a second now but the bad news is I broke one of the red LED's on the tube socket   and now have sound out of 1 channel ( left speaker

The Led's not glowing up and is broke on one of the legs

also I swapped around the little green pcb boards to see if the noise would switch channel when rerouting the wires just to see as the noise was much louder in the left channel
(dont know if these would of worked tho)

anyway do you think I'll be ok now with just installing a new LED ?

I went to order some LEDs but the delivery charge  is so high (£15 delievery on 1 website and a min spend £20 on another!
So I emailed bottlehead parts to see if you can help me and send me some.

Thank you   

[JamieMcC]

 I found these the best option when shipping costs and waiting times are considered mine took two days to arrive.

http://www.ebay.co.uk/itm/5-X-LED-SUBMIN-RED-Part-HLMP-6000-/390614571864?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item5af2715b58

5 X LED, SUBMIN, RED, Part # HLMP-6000 £3.16 free UK delivery. They worked fine in my Crack

Edit, they can also be brought individually but handy to have a few spare

[Hornet900]

I found these the best option when shipping costs and waiting times are considered mine took two days to arrive.

http://www.ebay.co.uk/itm/5-X-LED-SUBMIN-RED-Part-HLMP-6000-/390614571864?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item5af2715b58

5 X LED, SUBMIN, RED, Part # HLMP-6000 £3.16 free UK delivery. They worked fine in my Crack

Edit, they can also be brought individually but handy to have a few spare

Thank you Jamie 

[Hornet900]

hello guys

I've replaced the LED that I broke while I was moving the wires near the tube socket  (right channel went out ) but still no luck unfortunately 

I removed the speedball  put it all back to stock and it worked fine...silent as a mouse with no speedball.

So I reinstalled the speedball with new wires connecting to the solder tabs  in case one of the wires got broke but no luck, I also check all the soldering touched up the boards and they all look good  red LEDS work.   (when turning on the amp the 2 small boards light up 1st before the large board if thats any help?) and the noise starts soon as the 2 leds light up on the tube socket.

Still got this humming buzzy noise sometimes it sounds like wind blowing aswell,....sometimes the noise can go with the stock power tube but then the noise can start with amp warmed up after 30mins 1 hour. Its random.

With the  tung sol  5998 tube it's always there at all volumes (only at %0 volume and 100% the noise will change gets louder at 0% and 100% volume)

I poked  the wires with a lolly pop stick and the  middle white wire  on the volume pot that goes to the tube socket makes the noise,  If I move poke this wire at the pot the noise can stop and it can also go louder.... The noise always come back even if I've stopped it moving this wire ....I can make it go silent moving this wire. 

I replaced the wire but the noise didn't go away  connection it good   

Could it be the tube socket or volume pot?

Sometimes its both channels and sometimes its louder in the left.

Thanks


Edit : touching this white wire changes the sound from buzzing to a hum...touching the white wire at the tube socket does the same noise.

[Hornet900]

Could somebody please tell me if this tube socket is a drop in replacement? no cutting !

http://www.hificollective.co.uk/catalog/audio-note-chassis-mount-base-vbase015-p-1003.html?osCsid=lglvv66primjt7730ocgk6mun3


or this one?

http://www.hificollective.co.uk/catalog/ceramic-chassis-mount-base-pack-p-4619.html

I've also ordered a new volume pot this one

http://www.hificollective.co.uk/catalog/100k-tocos-cosmos-rv24-stereo-potentiometer-p-9215.html

[Paul Birkeland]

I believe the first socket will work.

You may have some solder flux that dribbled down into that tube socket contact.

You can use a syringe and alcohol to wet it down in there, then use your least favorite tube to scrape out any debris by inserting and removing the tube in the alcohol wet socket 5-10 times. 

Good work hunting this down.

-PB

[Grainger49]

There are a couple of methods to clean tube sockets in the FAQ Thread.

The problems with replacing the tube socket is it might not be the same diameter, the screw holes might not line up and it requires lots of delicate removal and replacement.  It is just a pain.

[Hornet900]

thanks for chiming in much appreciated thanks

I tried the method PB with the tube in and out but no luck mate... I dont have any alcohol cleaner  ( I do have some computer CPU cleaner its called akasa Tim cleaner but didn't know if it be ok,   doesn't say acohol cleaner on the back .  Its a citrus based cleaner it says on the front and  on the back says contains "Aliphatic hydrocarbons .30% BHT" .

Well i think its definitely something to do with that wire , at the pot connection i can make it go silent and moving the wire half way down ,  but at the socket its much harder to make it go silent, I get more hums and gets louder poking it  there ,  So confusing for me 

well I ordered the tube socket grainger  should be fun will install the new pot  same time fingers crossed It work out as I love this amp,

Another thing is I did a voltage check again speedball voltage check and the connection at terminal 6 and 10 never give me a solid 000.0 its always moving  and I get a minus - reading I think it is?
like -000.2   -020.0  and it goes up a bit but not very high, just never a solid 000.0 does this mean anything?

My speedball voltage checks are

1.      71.6
2.      179.3
3.      000.0
4.      179.8
5.      75.8
6.      moving about
7.      99.7
8.      000.0
9.      101.4
10.     moving about
11.     000.1
12.     000.8
13.     185.0
14.     000.9
15.     201.6
20.     001.0
21.     221.7


Oh and i forgot to say today I'm getting some channel imbalance too ...right channel is louder ... left channel can go quieter

Thanks again