Wow, this T7 phono stage has really come to life

dvb · « **on:** 4 May 2004, 04:16 pm »

Thanks to you all for bearing with my on-going queries and comments about the phono stage in the T7SL pre and tube rolling.

The tubes for rolling have been ordered, and have not yet arrived, and I've mainly been listening with my WPP100C phono pre.

After a day of doing so yesterday, I decided to try the T7 again. Wow! It sounded terrific. The articulate bass I had been missing was there in spades, along with lots PRAT excitement.

So, maybe the unit needed more burn-in, who knows. I am still looking forward to the tube rolling, but, as is, it seems I will be able to bear parting with the WPP100C after all.

zybar · « **Reply #1 on:** 4 May 2004, 06:41 pm »

david,

I thought the tubes for the phono are on all the time...

Although I had stopped using my TT a while back, I can't imagine they needed lots of break-in - who knows?

Glad you are enjoying the unit...

There was a reason I bought it in the first place....

George

dvb · « **Reply #2 on:** 4 May 2004, 07:14 pm »

You are right George, I can't quite figure out why this has "bloomed" so well for me -- burn-in doesn't entirely make sense, although maybe just being on is not the same as having signal run through it.

Maybe it is some psycho-acoustic thing in me -- getting use to the AVA sound or something -- but I really think it is a change in the hardware.

JoshK · « **Reply #3 on:** 4 May 2004, 07:15 pm »

I think Caps need signal run through them to burn-in, i.e. need to be charged, drained and recharged.

avahifi · « **Reply #4 on:** 5 May 2004, 11:32 am »

We would suggest that the "burn in" factor is almost all psycho-acoustic. The equipment is not changing, you are just learning more about what it is really doing. There is so much real information there, presented correctly, especially in inner detail and definition, that it is hard to hear all that at first.

At my test evaluation, we almost never have any "burn in" effects. The equipment being tested sounds the same right off the assembly bench, test bench and playing music for the first time. We give it about 5 minutes to form all the capacitors the first time before serious listening. There are no differences at all between properly working brand new units and my reference units. Rare initial defects in materials or assembly are always found at the test bench, even before listening sessions.

One example of "burn in" here is the listening room. The overall sonic characterists of the listening room here in Woodbury is very different from our old room in Burnsville. At first this new room sounded very strange to all of us. Now after 6 months of use, it sounds just fine and has dropped out of the listening experience. Certainly we did not "burn in" the room, we just burned in our preceptiion of the room.

We would suggest the same thing is happening with you when new equipment with a very different and better sonic abilities goes into your music system.

Frank Van Alstine

vrs · « **Reply #5 on:** 5 May 2004, 01:55 pm »

Burn in process may be some thing similar to having a sex for the first time and after seveal weeks or months.
There may or may not be any change in measuerments or it may be psychoadjusting or getting used to and familiarity.

dvb · « **Reply #6 on:** 6 May 2004, 12:23 am »

Much as I enjoy the Hi Fi hobby, I'm not sure I can take the sex analogy too far!

I did want to post a thread clearly praising the T7 stage -- I had been a bit negative about it in previous threads and thought it only fair to correct that impression "for the record"

However, I agree that there are both subjective and objective things going on when a new piece comes into the system. Subjective things ranging from cognitive issues (aural memory)to emotional issues ("God, was that expense worth it?")

So, enough with Psychology 100

I still have the passive pre it replaced (FT-LW1), so just for fun I'll go through the original process again -- run the Wright through the passive, then through the T7 line stage, then just use the T7 phono stage.

(And all that before doing any tube rolling!)

dvb · « **Reply #7 on:** 23 May 2004, 06:03 am »

My JJ Tesla 12AX7As arrived from Triode on Friday, and popped them in about noon, played side 1 of Zaca, than first cut on side 2 where I listen for Ray Brown's bowed bass -- same experience was with the initial listening I had reported -- not getting that articulated bass.

After some hours (sorry, neglected to note exactly), they sounded bettter

Now, about 16 hours later, I have played the bass again -- sounds great (as it did in time with the "stock" EH tubes).

As both the EH and JJs seem to have broken in, some "rolling" comparisons may be in order.

Thanks to all for you input.

pds · « **Reply #8 on:** 23 May 2004, 02:13 pm »

A far better tube to use is the 5879. This is a hi-fi tube and will give better performance in any equipment. You can replace a 12AX7 tube with a 5879 but not vice versa. If a system calls for a 5879 you must use that tube only.

avahifi · « **Reply #9 on:** 23 May 2004, 02:41 pm »

Well duuuaaa, the 5879 tube is a pentode, not a dual triode as is the 12AX7. It is not a direct replacement. Don't try that. Ah such wonderful advice here in AudioCircle.

Frank Van Alstine

avahifi · « **Reply #10 on:** 23 May 2004, 02:42 pm »

http://www.triodeel.com/5879p1.gif

pds · « **Reply #11 on:** 23 May 2004, 06:42 pm »

Sorry for the misinformation. I referred back to an old RCA manual and the 6681/12AX7A is a direct replacement for the 12AX7WA, the 12AX7A/ECC83 is considered a similar tube.. Let's see if you can find fault with that.