Tube Sockets & Tube Pins

Discussion - HT-1 amplifiers
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Classicplayer
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Thu Feb 26, 2015 6:53 pm

My HT1R combo was sounding a little lifeless and not as bright sounding as it did when 4 months back, I put in a new set. I was discouraged after spending a tidy sum on these new replacements. So, as an exercise, I put in the previous pair which six months ago or so, also started to sound dull. Low and behold, this older set that I swapped back in today has brightend up the little gem of an amp again. Could it be that the normal working of the tubes out of their respective sockets and working them back and forth and in again sort iof "polishes" the contact area and removes some of the oxidation thus restoring the tone somewhat? How else can this discovery be explained?

Classicplayer

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thephantum
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Thu Feb 26, 2015 7:25 pm

It's possible. Personally, when changing tubes I always clean and re-tension tube sockets.

Since it's cathode bias, it could also be the amp responding to the different bias curves of the different tubes (even tubes of the same brand can have bias differences). Or, if the tube sets are of different brands, you might be hearing those differences. More than likely, it's a combination of all the above factors.

Honestly, I would try doing test recordings of each tube set...same settings, same mic position, same guitar, etc. Then you can really do an objective listening test and map out the differences between each set.

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Classicplayer
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Thu Feb 26, 2015 7:42 pm

thephantum wrote:It's possible. Personally, when changing tubes I always clean and re-tension tube sockets.

Since it's cathode bias, it could also be the amp responding to the different bias curves of the different tubes (even tubes of the same brand can have bias differences). Or, if the tube sets are of different brands, you might be hearing those differences. More than likely, it's a combination of all the above factors.

Honestly, I would try doing test recordings of each tube set...same settings, same mic position, same guitar, etc. Then you can really do an objective listening test and map out the differences between each set.

Both sets are Tung-Sols. I also have a third set the same brand. I will lean the sockets, but not sure what' s
the safest solution to use. Nothing has changed when noticing the increased highs except the taking of one pair out and re-using an older pair. I have a feeling that then re-curing heating and cooling of the pins causes oxidation over time.

Classicplayer

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thephantum
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Thu Feb 26, 2015 9:55 pm

So just to make sure I have this straight: you have 3 sets of tubes, all the same brand (TungSol):
  • Set #1 - brand new
    Set #2 - old, replaced set#3
    Set #3 - oldest
...and set#3 sounds better then both set#1 and set#2?


As far as cleaning pins and sockets:
  • On the sockets, you can use any contact cleaner and a q-tip. I usually use DeoxIT Gold. http://www.amazon.com/gp/product/B003D8 ... UTF8&psc=1
    Image

    You can use the same on the tube pins, but it intentionally leaves a residue behind...which I don't like getting on the glass. Besides, by using it on the sockets, some will make it's way onto the pins anyway. So on tube pins, I use isopropyl alcohol, but not the 91% drugstore type....the 99.9% electronics grade stuff.
    http://www.amazon.com/gp/product/B005DN ... UTF8&psc=1
    Image

    In both cases, I find a wodden handle q-tips to last the longest and work best, but a normal q-tips will do the job...you'll just end up using one or two more. :mrgreen:

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Classicplayer
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Thu Feb 26, 2015 11:42 pm

None of the three pairs are not what you'd call "old" or well-used. All tubes are Tung-Sol labeled. No one pair is better or worse than the other pairs. None have had more use than the others, either. The one constant between the three pairs is that after a few months (4 or 5) the highs start disappearing. When it happens again as I suspect it will, I'll swap pair #3 in to see whether that pair, again, produces the bright highs inherent in this HT1R.

Thanks Phantum for the advice. It seems there is also another post on these forums about cleaning the sockets and pins. I was beginning to think that there was something really wrong with the amp.

Classicplayer
Last edited by Classicplayer on Thu Feb 26, 2015 11:55 pm, edited 1 time in total.

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thephantum
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Thu Feb 26, 2015 11:53 pm

Yea, it could be exactly what you initially said....that the actual act of changing tubes roughs up the contact points enough so that everything makes a better connection.

The next time it happens, a really interesting experiment would be to pull the tubes, clean everything and then put the same tubes back in.

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Classicplayer
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Thu Feb 26, 2015 11:58 pm

thephantum wrote:Yea, it could be exactly what you initially said....that the actual act of changing tubes roughs up the contact points enough so that everything makes a better connection.

The next time it happens, a really interesting experiment would be to pull the tubes, clean everything and then put the same tubes back in.
I hadn't thought of that. That would be even more proof. I'm coming up on the 3rd. year of ownership this May.

Classicplayer

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Classicplayer
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Sat Mar 07, 2015 12:39 pm

Phantum,

After warming up the HT1R combo with a bout 1/2 and hour or 45 minutes ofmplaying time, the highs vanish again. This model has been described as "warm sounding" in some reviews of it. So, I don't know if it is oxidation on the pins and tube sockets, the less than stellar tube offerings these days, or just the nature of the beast.

In my case, I have ordered the two products you posted above and I'll report back what results I have with both. Makes me want to tear my hair out, as the amp in all other respects was a good choice for me. Note: I had a Fender Blues Jr. "green board edition" some years ago and as I remember, it too exhibited the same loss of highs. It had 2 EL84!tubes and 3 12Ax7 tubes; all being the JJ brand.

Clasicplayer

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thephantum
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Sat Mar 07, 2015 4:40 pm

Classicplayer wrote:After warming up the HT1R combo with a bout 1/2 and hour or 45 minutes ofmplaying time, the highs vanish again.
Is this repeatable? In other words if you turn it off and come back the next day, does it do the same thing...highs are there and then they vanish?

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Classicplayer
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Sat Mar 07, 2015 7:27 pm

Is this repeatable? In other words if you turn it off and come back the next day, does it do the same thing...highs are there and then they vanish?[/quote]


Not sure just yet. I played today for an hour at a higher volume on the clean channel and highs were improved. Gain was around 10:00am, volume was dimed and ISF at 9:00am; same for reverb. Guitar is a Les Paul and I had the neck pickup volume at 7.5 to 8. I need to repeat that next time and compare.

Classicplayer

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