BHK Preamp tube rolling

Audio Components Amplifiers
1264

I used a Telefunken 12AT7 and a pair of TFK 12AX7s in the phonostage of my old Conrad Johnson PV10A and thought they were first rate. Clean, clear and quite neutral.

Used a pair of Bugle Boy 7318s for the linestage in the 10A. Another top tier tube IMO. Bugle Boy has always been among my favorites. Even Bugle Boy 6DJ8 that were Tektronix pulls I used in other CJ preamps and amps were darn good – so musical.

Looking forward to your thoughts after you try the TFK.

Edit: Andy is an institution when it comes to vintage tubes.

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1265

Serhan, thank you for that information. I had that squeal once with the Gold Lion tubes but never with any other tube that I have tried in the preamp. I will give the gold lions another chance. To tell you the truth I have never came across a tube that I like as much as the nos conn/12au7 that I am currently using.

1266

Hi John,
I hope you like the GLs. Good NOS are getting ever costlier and harder to source!

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1267

Swapping back from TAD to Gold Lion 12AU7 tubes I have to definitely admit that this is my sweet spot.

On the warm side of neutral but richer sound, tight basses and a sort of magic I no more can’t live without.

It’s a real pleasure when you find a balance where all of your expectations make you feel that everything is in the right place.

I can say now that I want to stop rolling for a while…

Enjoy!

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1268

I wiped down the tubes, both the glass and the pins, then reseated them a few times. The one problem tube no longer makes a clicking sound when adjusting the preamp volume, and now only sounds slightly noiser than the other tube.

Plus, although these tubes were sold as used, they still seemed to need some hours to settle in,
either that or the pins just needed to be cleaned off, because they’re sounding absolutely amazing, like having a new preamp.

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1269

The settling-in happens even with used tubes I’ve discovered.

Glad to hear how much you like’em. :+1:

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1270

Are people manually resetting the tube hour tracker on the BHK? Think I spaced out that step last time.

1271

I try and reset it each time when changing tubes. I keep a small piece of paper with each tube pair showing hours and dates installed or removed. Mainly because my memory for those type of things cannot be trusted. And my OCD kicks in if I dont record the data.

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1272

This strikes me as smart, OCD or not.

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1273

Agree - Any time I pull tubes out and add new, I take the hours and write the date & hours on-each tube box, then reset the BHK.

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1274

Thankfully I’m not using $1500 tubes. Ha!

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1275

What is the normal hours one could expect from the stock tubes. I just purchased used one from TMR, and it has many hours on it.

1276

They may go to 10,000 hours before needing replacement. The best way to tell is keep another set on hand and swap them out maybe once a year. If you cant tell any difference then put the used ones back in for another round. The OEM ones I just took out of my preamp had 1800 hours on them and they were still in fine musical shape.

1277

Does anyone know if the Raytheon Glossy Long Black plate 12AU7 tubes with the Top Halo getter variety, are the same as the ones with the O getter, with everything else about the tubes being the same?

1278

Removed my first set of Tungsram NOS tubes from my BHK Preamp. I noticed slight hissing noise coming from my speakers. The tubes had just under 1100 hours on them.

1279

Gary

Depending on the seller you will see the same tube described both ways.

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1280

6volt or 12 volt?

1281

6v I believe.

1282

6v tubes were too noisy for me when I tried them. When I switched back to 12v things were dead quiet.

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1283

I have had the same experience.