Gold Lion AX7 in tube preamp

It’s not a race run it in when you get back. Odds are nothing will happen but if it red plates it could smoke your amp and worse smoke your house.

When you get back run it 100-200 hours see what happens. It’s a very detailed tube and should smooth out. If your looking for a clean and detailed tube the GL is it, if you want a Mullard sound you will never get that.
 

if  you are looking for Goldie locks tube the RCA may be it even though it’s more of a guitar amp tube. It falls between the Mullard and Telefunkens Everybody’s taste is different.

Turn off if leaving the house for holiday.

Mullard for the 12A7T tubes which are also new. Since they are just driver tubes I only swapped the Tungsols back in and everything was good again. It it safe to leave a tube preamp on for days at a time? I’m leaving for 4 days over the 4th and could let them cook in. 

I have a 12ax7 Tungsol in there right now and it’s sounds really good. I just thought the Gold Lion would be an upgrade. Bought from the Tube Depot. It’s says it’s a Russian one on the tubes. 

Check with your manufacturer if trying 5751

For lower gain you can substitute a 5751 for the 12ax7 in many circuits.

@yogiboy 

Yes it’s the correct replacement. 

For warmish/tubey sound;

Amperex 12 AX7

Mullard 12AX7

RCA 12AX7 long plate

Are you sure that a 12ax7 is the correct replacement tube for that preamp? 

@yogiboy 

Using a Jolida Fusion preamp with some upgrades into a Benchmark AHB2. 

I have purchased a number of new tubes, especially 12ax7, 5751, el34 and kt77 and have to say that by the end of the listening session they were pretty much sounding as they were going to.

Once purchased a set of relatively inexpensive 12ax7s based on a recommendation by a member here.  They sounded bad when first used and stayed that way.

What tube preamp are you using?

If your talking 12ax7’s I believe they make one from Mexico and one from Russia. The Russians being the better of the 2 I’ve heard.  I had some Russian ones that came stock with an amp I bought. They were pretty good for new production.

They tend to share sonics with Telefunkens not as good but resemble each other. When I pulled the gold lions and put in the Telefunkens that’s when you see the big difference. First thing I noticed was sound stage then how much more natural the Telefunkens were and I’ve never thought of Teles being relaxed and natural. 
 

You really notice a difference when you compare the GL to the Mazda, mullards, RCA’s, Tungsram and others but you would expect this comparing new production to vintage. For a new tube I think they are pretty good but there not cheap either. You can buy used vintage 12ax7 that test new for the price of the Gold Lion.

@glennewdick ,

Did they sound anything like I’m describing before full breakin? It would have to get pretty night and day better for me to be happy with them. 

It took mine about 200hours before they sounded great, after the break in they were some of the best new production tubes I've encountered specially for the money. they are not an overly warm sounding tube more neutral then most.