[bcowen]

I’ll try a higher temp for the next pin job. I see your logic here for de-soldering as the shortest amount of time the better. I’d also note that using a liquid flux would be a good idea? I always use a flux dispensing pen. Now is it recommended for pins?

If I'm being lazy and just doing a reheat and adding a bit of solder I don't mess with the flux. If I'm doing a proper 'good audiophile' suck'n'resolder, I add a little flux just to help clean out the internals (being careful to wipe any excess off the outside of the pin before heating it). I like this paste flux just 'cause it's easy to dispense and easy to control where it goes, and the tip on this particular one is exactly the same diameter as an octal tube pin. But any good flux would serve the same purpose.

https://www.amazon.com/MG-Chemicals...ywords=mg+chemical+flux&qid=1605983192&sr=8-5

 

[bcowen]

Here's an age test: how many of you know what an ignition point file is? Some of us already know because, yes, we're that old. More importantly, this file works great for filing off any excess solder you may get on the outside of the pin. Narrow and thin enough to get between the pins easily.

https://www.amazon.com/gp/product/B0067YFPBC/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[Brubacca]

Okay, yeah nice. I say go for it and let us know. Probably clearer highs and a better midrange response incoming.

So I did it. Massive hum in both channels. I can't listen to it because of the hum. I'm not freaking out though. It seems the hum should get less after a day or two. I would say definitely better with the new tubes, but the hummmmm. Has to go away.
Here are my 2 tube amps#

 

[JKDJedi]

How does it sound?

Add it up there with the Mount Rushmore of tubes..

 

[JKDJedi]

Here's an age test: how many of you know what an ignition point file is? Some of us already know because, yes, we're that old. More importantly, this file works great for filing off any excess solder you may get on the outside of the pin. Narrow and thin enough to get between the pins easily.

https://www.amazon.com/gp/product/B0067YFPBC/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Have something similar to that in chi fi form.. and now I'm really thinking of getting in an updated iron, the flux I use ( only when pins don't heat up quick enough) was recommended by @Paladin79 , the solder used for the pins I think has enough (flux) in it for this use imo. Check out the solder pulled out of the pins last night, they seem to be fully intact.. thinking 750 degrees might be the ticket.

 

[JKDJedi]

So I did it. Massive hum in both channels. I can't listen to it because of the hum. I'm not freaking out though. It seems the hum should get less after a day or two. I would say definitely better with the new tubes, but the hummmmm. Has to go away.
Here are my 2 tube amps#

Them "new" Tung Sol 6sn7gtb tubes are notorious for hum. Let it bake for a few days (without the power tube inserted) should help. This from the Tube Store..

1. Power off the amp and remove the 6AS7/6H13C power tube. This will keep the unit from over heating during this burn-in procedure.

2. Install your new 6SN7 tube and power the amp on again.

3. Wait. And keep waiting. We find that by approximately 72 hours will do.

4. Power off and re-install the 6AS7/6H13C power tube.

5. Connect your favorite headphones and power the amp on.

You should find the hum in the left channel has completely disappeared. At the least you’ll notice it’s much quieter and likely only need one more day to get it completely quiet.

I realize you can modify the amplifier and add a couple capacitors to solve this but the instructions above will “fix” it for free so give it a try.

https://blog.thetubestore.com/burning-in-6sn7-tubes-for-the-dark-voice-336se-headphone-amp/

 

[Brubacca]

Them "new" Tung Sol 6sn7gtb tubes are notorious for hum. Let it bake for a few days (without the power tube inserted) should help. This from the Tube Store..

1. Power off the amp and remove the 6AS7/6H13C power tube. This will keep the unit from over heating during this burn-in procedure.

2. Install your new 6SN7 tube and power the amp on again.

3. Wait. And keep waiting. We find that by approximately 72 hours will do.

4. Power off and re-install the 6AS7/6H13C power tube.

5. Connect your favorite headphones and power the amp on.

You should find the hum in the left channel has completely disappeared. At the least you’ll notice it’s much quieter and likely only need one more day to get it completely quiet.

I realize you can modify the amplifier and add a couple capacitors to solve this but the instructions above will “fix” it for free so give it a try.

https://blog.thetubestore.com/burning-in-6sn7-tubes-for-the-dark-voice-336se-headphone-amp/

Thanks. That's where I bought the tubes from! I will do that right now. Not sure how I missed that.

 

[therremans]

Yeah sorry I didn’t mention that, it’s brought up often. That was my first tube myself with an RCA. The hum was there I think in my left channel only. The bake for me I think took about 12 hours or so and the tube was silent. Just check back once in awhile

 

[Paladin79]

Have something similar to that in chi fi form.. and now I'm really thinking of getting in an updated iron, the flux I use ( only when pins don't heat up quick enough) was recommended by @Paladin79 , the solder used for the pins I think has enough (flux) in it for this use imo. Check out the solder pulled out of the pins last night, they seem to be fully intact.. thinking 750 degrees might be the ticket.

[/QUOTE

I am trying to follow what you are saying here. Adding flux causes the pins to heat up faster? Flux cleans the metal to allow solder to adhere.

Looking at solder I remove from pins tells me absolutely nothing and I have been doing this a long time lol.

It is very difficult to see inside the pins so I take no chances, since the original solder failed. It is true there is flux inside new solder but at times, like dealing with some new connectors, you have to apply a lot of heat to get the solder to adhere with just the flux but that is out in the open where you can see it lol. You cannot see the condition of the inside of the pin nor the wire extending down from the tube. It is entirely possible to surround that wire with solder and still have a poor connection because it is not clean enough to allow for a good solder joint. I personally use 800 degree tips and always use liquid flux inside pins that can be 50 years old.

 

[JKDJedi]

I am trying to follow what you are saying here. Adding flux causes the pins to heat up faster? Flux cleans the metal to allow solder to adhere.

Looking at solder I remove from pins tells me absolutely nothing and I have been doing this a long time lol.

It is very difficult to see inside the pins so I take no chances, since the original solder failed. It is true there is flux inside new solder but at times, like dealing with some new connectors, you have to apply a lot of heat to get the solder to adhere with just the flux but that is out in the open where you can see it lol. You cannot see the condition of the inside of the pin nor the wire extending down from the tube. It is entirely possible to surround that wire with solder and still have a poor connection because it is not clean enough to allow for a good solder joint. I personally use 800 degree tips and always use liquid flux inside pins that can be 50 years old.

there's solder at the very bottom of the pins, I can see them without aid of glasses. if they look suspect, cracked dark grey, med grey, not silver... uneven... partially missing... then I resolder it if I'm not lazy that day...(which is often ) and I was having trouble with one pin last night.. did not want to heat at all... my iron tip might be going out, so I dabbed some flux in there....it heated quick. That's my experience.

 

[Paladin79]

there's solder at the very bottom of the pins, I can see them without aid of glasses. if they look suspect, cracked dark grey, med grey, not silver... uneven... partially missing... then I resolder it if I'm not lazy that day...(which is often ) and I was having trouble with one pin last night.. did not want to heat at all... my iron tip might be going out, so I dabbed some flux in there....it heated quick. That's my experience.

yes one can normally see solder at the bottom of the pin, I best leave this conversation, take care.

 

[JKDJedi]

yes one can normally see solder at the bottom of the pin, I best leave this conversation, take care.

.. was it something I said..

 

[bcowen]

Have something similar to that in chi fi form.. and now I'm really thinking of getting in an updated iron, the flux I use ( only when pins don't heat up quick enough) was recommended by @Paladin79 , the solder used for the pins I think has enough (flux) in it for this use imo. Check out the solder pulled out of the pins last night, they seem to be fully intact.. thinking 750 degrees might be the ticket.

Aw, man. Get rid of that PlaySkool soldering iron and get a real one:

https://www.amazon.com/Weller-WE101...&qid=1606001657&sprefix=weller,aps,165&sr=8-5

While you're at it, get a chisel tip for it to do octal pins (and DO NOT cheap out on the Chinese junk...get a real Weller tip):

https://www.amazon.com/KD-Tools-ETD...s=weller+we1010na+tips&qid=1606001862&sr=8-34

Hakko's are good too, but I've had my Weller for 25+ years and haven't even had to replace the iron at this point (although it's nearing that point)..

https://www.amazon.com/Hakko-FX888D...dchild=1&keywords=hakko&qid=1606002373&sr=8-1

 

[bcowen]

Thanks. That's where I bought the tubes from! I will do that right now. Not sure how I missed that.

In addition, one thing that's easy to check (and fix if needed) is the earth ground connection from the IEC socket to the amp chassis. I had a low level hum with the Chinese tubes when I first got mine (not loud, but audible), and once I scraped the paint and got a good ground connection the majority of that hum went away. All was good after that....until I stuck in a Foton 6N8S, and the DV hummed like crazy. The Fitz mod fixed that problem, but why it was SO loud only with the Fotons (3 different ones) I'm at a loss to explain. Didn't do it with the Melz...

 

[bcowen]

I am trying to follow what you are saying here. Adding flux causes the pins to heat up faster? Flux cleans the metal to allow solder to adhere.

Looking at solder I remove from pins tells me absolutely nothing and I have been doing this a long time lol.

It is very difficult to see inside the pins so I take no chances, since the original solder failed. It is true there is flux inside new solder but at times, like dealing with some new connectors, you have to apply a lot of heat to get the solder to adhere with just the flux but that is out in the open where you can see it lol. You cannot see the condition of the inside of the pin nor the wire extending down from the tube. It is entirely possible to surround that wire with solder and still have a poor connection because it is not clean enough to allow for a good solder joint. I personally use 800 degree tips and always use liquid flux inside pins that can be 50 years old.

You're using 50 year-old flux? Dang, man. At least now I know what to get you for Christmas.