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JTVG Backstage Pass
Joined: 21 Jun 2007 Posts: 433
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Posted: Wed May 26, 2010 9:27 am Post subject: Avalon 737SP - New tubes |
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For awhile now, it's seemed like my Avalon has been a bit noisier than it should be and the sound wasn't that impressive. Listening back a couple of years ago, I couldn't be sure, but it did seem a little less hissy back when it was new and VO was stronger.
So I figured I'd give new tubes a shot.
I replaced the four stock Sovtek 6922's ($10 per) with JAN Sylvania 6922's ($34 per) from Tube Depot and wow, what a difference. The signal is a lot louder and the hiss is pretty much gone. I would highly recommend this upgrade.
Here's an AIF file with the noise floor before then a little VO, then after the tone, the new noise floor with a little VO recorded with the new tubes. The noise floor meter actually runs higher with the new tubes due to the louder signal. But all the hiss is gone and it's much much cleaner. _________________ Joe Szymanski
http://www.joethevoiceguy.com
Last edited by JTVG on Wed May 26, 2010 9:28 am; edited 2 times in total |
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JTVG Backstage Pass
Joined: 21 Jun 2007 Posts: 433
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Posted: Wed May 26, 2010 9:28 am Post subject: |
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Argh, meant to put this in the Gear section. Sorry. _________________ Joe Szymanski
http://www.joethevoiceguy.com |
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Rob Ellis M&M

Joined: 01 Aug 2006 Posts: 2385 Location: Detroit
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Posted: Mon Jun 07, 2010 8:26 am Post subject: |
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Hey Joe,
Great stuff. I have the 737 also and the noise floor isn't the best.
Any quick tips on how to replace the tubes? I've never done it myself.
My Avalon is a little over two years old so this might be a good time. |
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Mike Sommer A Hundred Dozen

Joined: 05 May 2008 Posts: 1222 Location: Boss Angeles
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Posted: Mon Jun 07, 2010 1:05 pm Post subject: |
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A quick note on tubes: Any JAN series tubes are military grade tubes.
They tend to be a little quieter, have less microphonics and last longer.
Here is a great vid on what a Microphinic tube sounds like:
http://www.youtube.com/watch?v=QM2qWZYbInI
The coveted versions of the 6922 tube are Amperex, RCA and Philips.
The 6922 is the premium version of the 6DJ8 tube, a 9-pin medium gain dual
triode vacuum tube. Intended for use in military test equipment.
The Amperex 6922 were made in the US not Holland (at one time it was
a requirement to manufacture military equipment in the US- what happened
to that?) and the quality is spectacular. There is also what is known as a
"pinched waist" version of this Amperex tube (there was flaw in the
machine that finished the tube assembly) what you get is an incredible
sounding tube, with a heart stopping price-- if you can find it. Last I heard
there were 9 left in the world that are in NOS condition.
The RCA 6922 were made in Germany, and are very good too, but are a
little hard to find. _________________ The Blog:
http://voiceoveraudio.blogspot.com/
Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong. |
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JTVG Backstage Pass
Joined: 21 Jun 2007 Posts: 433
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Posted: Mon Jun 07, 2010 2:50 pm Post subject: |
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It's super easy, Rob. Just power down, take off the cover, gently rock the tubes out of their slots and push the new ones down in their place. Voila!
If the JAN's give that much improvement over Sovtek's, I can't imagine how awesome some of the ones Mike listed would sound. _________________ Joe Szymanski
http://www.joethevoiceguy.com |
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Mike Sommer A Hundred Dozen

Joined: 05 May 2008 Posts: 1222 Location: Boss Angeles
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Posted: Mon Jun 07, 2010 5:40 pm Post subject: |
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Just to be clear:
JAN means "Joint Army Navy" these tubes were manufactured for the
military. What we have left today is the surplus of those huge orders.
For this particular tube:
The standard consumer U.S. tube is the 6DJ8.
In Europe it is know as the ECC88.
You'll often see tubes marked ECC88/6DJ8
The 6922 is the Premium version.
E88CC and E88CC/01 are the European versions of the 6922
CV2493 is the Europe military version of the E88CC/01.
JAN-6922 U.S. military version.
CV2492 the British version.
E288CC is about a half inch taller, and is cream of the crop and most people
don't know about them. This tube has most if not all of the desired sound
and quality of the worshiped Cca tube, but at the price of a garden variety.
The Cca tube has matched triode sections, low noise screening, 10,000 hr.
heater life expectancy, controlled frame grid winding, low microphonics and
on and on.
7308 is the ultra 6DJ8 tube. With a matched triode sections and have
very tight specifications.
E188CC It is basically the European equivalent to the 7308
So any of the above tubes will work in your Avalon.
This will blow your mind. Enjoy
http://www.youtube.com/watch?v=gl-QMuUQhVM
http://www.youtube.com/watch?v=9S5OwqOXen8&NR=1 _________________ The Blog:
http://voiceoveraudio.blogspot.com/
Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong. |
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Rob Ellis M&M

Joined: 01 Aug 2006 Posts: 2385 Location: Detroit
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Posted: Wed Jun 16, 2010 6:17 am Post subject: |
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Joe,
How old were the tubes in your Avalon that you replaced?
And I'm wondering, is the louder signal any different than if you just amplified the soundwave after recording? |
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JTVG Backstage Pass
Joined: 21 Jun 2007 Posts: 433
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Posted: Wed Jun 16, 2010 6:54 am Post subject: |
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Rob,
I bought it new in September 2008.
When comparing the two samples at the same level, the difference is indeed more subjective. Though having the hiss out of the way definitely makes the VO pop more and brings greater definition. If you have any noise that is inherent to the Avalon that you are currently gating out, it's likely that being able to back that gate off as the noise is reduced will make your VO shine a little brighter.
There's a tiny bit of mouth noise in between the sentences in the 2nd sample on the file I posted. That never would have come across with the old tubes. I find myself having to be more mindful about things like that now that the clarity has increased. _________________ Joe Szymanski
http://www.joethevoiceguy.com |
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Rob Ellis M&M

Joined: 01 Aug 2006 Posts: 2385 Location: Detroit
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Posted: Wed Jun 16, 2010 9:09 am Post subject: |
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BTW Joe the only reasoning I'm asking is due to trying to decide whether to spend the $$$ on new tubes.....
Do you have your Output at the 12 0' clock? That's where I usually keep mine.
I can currently increase it and get hotter output, but then the noise floor goes up as well |
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JTVG Backstage Pass
Joined: 21 Jun 2007 Posts: 433
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Posted: Wed Jun 16, 2010 9:46 am Post subject: |
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I had my output around 12 and had the same problem. In fact, I've experimented with all kinds of input/output levels trying to find the highest level with the lowest noise floor and most of it was to no avail. It's now around 9, as 12 is way too hot with the new tubes. Definitely worth the money. In the grand scheme of things, $34 x 4 is a small price to pay to lower your noise floor that drastically. _________________ Joe Szymanski
http://www.joethevoiceguy.com |
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Rob Ellis M&M

Joined: 01 Aug 2006 Posts: 2385 Location: Detroit
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Posted: Wed Jun 16, 2010 10:04 am Post subject: |
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Thanks Joe. You sold me!  |
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JTVG Backstage Pass
Joined: 21 Jun 2007 Posts: 433
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Posted: Wed Jun 16, 2010 1:58 pm Post subject: |
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I think you'll be pleased, Rob. I'm a fan of purchases that really truly make noticeable improvements. Make sure to do an A-B if you have a chance. _________________ Joe Szymanski
http://www.joethevoiceguy.com |
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Gregory Best The Gates of Troy

Joined: 04 Aug 2005 Posts: 1853 Location: San Diego area (east of Connie and south and east of Bailey)
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Posted: Fri Jun 18, 2010 4:26 pm Post subject: |
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I've been thinking about a 737 but now am concerned about the noise floor. Is it that much of an issue with ther 737? _________________ Gregory Best
greg@gregorybest.com |
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ballenberg Lucky 700
Joined: 10 Nov 2004 Posts: 793 Location: United States
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Posted: Fri Jun 18, 2010 6:33 pm Post subject: |
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Not for me Greg. Never. It's great. |
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Mike Sommer A Hundred Dozen

Joined: 05 May 2008 Posts: 1222 Location: Boss Angeles
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Posted: Fri Jun 18, 2010 9:44 pm Post subject: |
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It's a very nice preamp.
But I'll let you in on a little secret. Try the Golden Age Pre 73.
The GAP 73 sounds just as wonderful as the Avalon.
Unless you need the processing and EQ of the 737, I say go for it. But
the GAP 73 is a clone of a Neve 1073, with all the deliciousness that comes with
this kind of class-A discrete preamp. With 80dB's under the hood, you can
drive a passive ribbon microphone with no problem, and I have, with no
noticeable noise with head room to spare.
And you can get one for 300 bucks, daddy-O.
Here you can learn a little about the 1073 along with a little audio of Mr Neve
talking about how he came about this little box of magic:
http://mixonline.com/TECnology-Hall-of-Fame/1970-neve-1073/ _________________ The Blog:
http://voiceoveraudio.blogspot.com/
Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.
Last edited by Mike Sommer on Sat Jun 19, 2010 2:02 am; edited 1 time in total |
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