[Alwayswantmore]

I want to dedicate this thread to questions new Isabella owners may want answered. I'm new to both the Isabella and tube equipment, so I'll post a few to get the ball rolling. Hopefully current owners and Vinnie can provide the 'As' or our 'Qs'.

Q: Do the tubes need to warm up before they sound their best? If so, about how long?

Q: This one will probably be in the manual, but what is the recommended break-in period?

Q: How many hours do these types of tubes operate before they need replacement?

Q: What about tweaks like tube rings (or what ever they're called that people put on tubes)? Do they help the sound? If so, which brands / types should we be considering?

Q: I assume that tubes are more sensitive to vibration than the Sig 30, any recommendations for isolation or vibration control?

Q: What else should a newbie to tubes know about the Isabella to get the best sound and longest life out of the unit???

[6rs]

Q: Do the tubes need to warm up before they sound their best? If so, about how long?
The Isabella-Sig30.2 combo profits from a 10-minutes warm-up. I do not know whether this is mainly due to the tubes in the Isabella.


Q: How many hours do these types of tubes operate before they need replacement?
This seems tube-dependent. Some tubes, like the Amperex 7308 military grade that Vinnie recommended in an other thread, are claimed
to live >10'000 hours

Q: What about tweaks like tube rings (or what ever they're called that people put on tubes)? Do they help the sound? If so, which brands / types should we be considering?
I tried mapleshade brass sleeves. They improve the sound. However, probably due to different expansion of the brass versus the glass, a tube got crushed (Tungsram). (Amazingly, it still kind of worked without the vacuum...?) So, on has to be careful with these. Also, some tubes have a somewhat irregular shape resulting in little contact area to the brass sleeve. Therefore I ordered some rings from Herbie's. They are easy to handle, and cheap. Their effect is beneficial as well.

Q: I assume that tubes are more sensitive to vibration than the Sig 30, any recommendations for isolation or vibration control?
I tried mapleshade brass feet and Boston Audio tuneblocks XT. I prefer and would recommend the tuneblocks.

Q: What else should a newbie to tubes know about the Isabella to get the best sound and longest life out of the unit???
I feel there is nothing really special to consider.

[Eadron]

Q: Do the tubes need to warm up before they sound their best? If so, about how long?

Q: What about tweaks like tube rings (or what ever they're called that people put on tubes)? Do they help the sound? If so, which brands / types should we be considering?

Q: I assume that tubes are more sensitive to vibration than the Sig 30, any recommendations for isolation or vibration control?

Q: What else should a newbie to tubes know about the Isabella to get the best sound and longest life out of the unit???

For what I have found so far:

Q1: about 20 or so minutes for warm-up needed to sound it's best imo.
Q2: never tried any rings but definitely worth trying
Q3: the RWA gear is as sensitive as anything out there to vibration. I've just been playing around with Ikea lack table and the RWAs stacked on it. No good. Next put them on finite -elemente signature rack and everything settled and sounded, oh so good. They definitely are worth for proper isolation.
Q4: Just listen to music and enjoy  .

jouni

[kitten]

Hmmm...

Being battery operated, I was kinda hoping the RWA gear would be more immune to the vibration / isolation considerations. And with such a small footprint it would seem a shame not to be able to just stack em and save space rather than have to space them out in a rack.

Did it really make that big a difference? I suppose side by side might be another option.

[Alwayswantmore]

Hmmm...

Being battery operated, I was kinda hoping the RWA gear would be more immune to the vibration / isolation considerations. And with such a small footprint it would seem a shame not to be able to just stack em and save space rather than have to space them out in a rack.

Did it really make that big a difference? I suppose side by side might be another option.

I have a Signature 30.2 and a Wadia 830 CDP, both in a basic Target rack (MDF -- nothing fancy). I use Ayre Myrtle wood blocks under the CDP and can hear a difference (I have tried Mapleshade triple points too). I tried the wood blocks under the 30.2 and was not able to discern a meaningful difference in my system. So my conclusion is there are no moving parts in the Sig 30, no transformer hum, etc. so the Sig 30.2 may not benefit as greatly from issolation treatments as say a CDP which has moving parts.

Now the Isabella has tubes, so I would expect it to potentially be more responsive to isolation treatments.

[Alwayswantmore]

Q: What about tweaks like tube rings (or what ever they're called that people put on tubes)? Do they help the sound? If so, which brands / types should we be considering?

A: Therefore I ordered some rings from Herbie's. They are easy to handle, and cheap. Their effect is beneficial as well.

6rs, which model? Please let us know how well they work. Link to Herbies... http://herbiesaudiolab.home.att.net/

[6rs]

6rs, which model? Please let us know how well they work. Link to Herbies... http://herbiesaudiolab.home.att.net/

Different models seem to differ in size only - model 9 fits the tubes as used in the Isabella.

[kbuzz3]

Hmmm...

Being battery operated, I was kinda hoping the RWA gear would be more immune to the vibration / isolation considerations. And with such a small footprint it would seem a shame not to be able to just stack em and save space rather than have to space them out in a rack.

Did it really make that big a difference? I suppose side by side might be another option.

I have a Signature 30.2 and a Wadia 830 CDP, both in a basic Target rack (MDF -- nothing fancy). I use Ayre Myrtle wood blocks under the CDP and can hear a difference (I have tried Mapleshade triple points too). I tried the wood blocks under the 30.2 and was not able to discern a meaningful difference in my system. So my conclusion is there are no moving parts in the Sig 30, no transformer hum, etc. so the Sig 30.2 may not benefit as greatly from issolation treatments as say a CDP which has moving parts.

Now the Isabella has tubes, so I would expect it to potentially be more responsive to isolation treatments.

i did not think i would hear a difference between myrtle v. herbies on my sig 30 chassis but i did.  Maybe b/c mine is the omega paneled version? Not sure, but ill experiment again in the next few weeks..but urge sig owners to at least try for themselves...its cheap-heck ill even loan you some blocks

[Eadron]

Hmmm...

Being battery operated, I was kinda hoping the RWA gear would be more immune to the vibration / isolation considerations. And with such a small footprint it would seem a shame not to be able to just stack em and save space rather than have to space them out in a rack.

Did it really make that big a difference? I suppose side by side might be another option.

You can get decent results even putting them on a hard floor; stacked or side by side or putting them on a table etc.

But, if you really wanna squeeze every bit of performance from the RWA gear, then dedicated rack certainly gives you the most. I have two pair of speakers right now, the Avantgarde Uno Nanos and the Omega Super Hemp Alnicos and especially with the SHemps, which are very revealing and very truthful by their nature, the difference when using quality rack was more than obvious. So I'm not going to dump my finite. It will stay as my dedicated audio rack and I can easily recommend it.

jouni

[Mariusz]

6rs, which model? Please let us know how well they work. Link to Herbies... http://herbiesaudiolab.home.att.net/

Different models seem to differ in size only - model 9 fits the tubes as used in the Isabella.

Not quite.
I have two latest models - both fit 6922 tubes.
Different materials used for the ring, dumpers (sort of silicon and metals), shape of dumpers, cuts...no cuts.......there is at least 4-5 different kinds for 6922 tubes along. I am using those on my vintage Scott but will try them with RWA Isabella.
What is great about Vinnie's preamp - it is low maintainess, well integrated and floor space saving foot print.
If you what to stock the amp and the preamp, I do not see the problem. However, I would use at least 2 stocked 3/4inch MDF or maple 1.5 " butcher block between components  and paint it matte black to match the RWA theme. To protect the components, you can use inexpensive iso-block made out of sandwhich cork and rubber.


Mariusz

[Alwayswantmore]

i did not think i would hear a difference between myrtle v. herbies on my sig 30 chassis but i did.  Maybe b/c mine is the omega paneled version?

kbuzz3, did you prefer the myrtle to herbies?

[6rs]

Not quite.
.......there is at least 4-5 different kinds for 6922 tubes along.


Mariusz

I could only find one other version, for guitar amps? Where did you find the various different HAL tube damper versions of the 6922 size?
Bruno

[Vinnie R.]

Hi Kent,

Q: Do the tubes need to warm up before they sound their best? If so, about how long?

The Isabella features an auto-mute delayed turn-on sequencing (approx. 40 seconds) to allow for adequate tube warm-up and stabilization and to eliminate turn on/off transients.  However, I have found that it is best to wait 5 to 10 minutes before critically listening.  After that, the tubes should reach their peak temperature and everything should be in equilibrium.

Q: This one will probably be in the manual, but what is the recommended break-in period?

Yes, per the manual:

While your Isabella line-stage preamplifier will sound very good right out of the box, before critically evaluating its performance we highly recommend allowing for at least 100 hours of total use (burn-in time) connected to your amplifier (in order to load the output) and playing music.  A sonic change will occur during this period that is the result of electrons flowing through the entire signal path of your Isabella.  The dielectric of the various capacitors will form with use, and the included tubes need time burn-in as well. 

Q: How many hours do these types of tubes operate before they need replacement?

You should get plenty of hours on them (a few years at the very least)... we are not running them on high B+ voltage, so they are being treated like gold in the Isabella 

Q: What about tweaks like tube rings (or what ever they're called that people put on tubes)? Do they help the sound? If so, which brands / types should we be considering?

I haven't played with tube rings like the Herbies yet - thing may or may not sound better with these things (it just might sound "different" but not necessarily better).

NOTE: The distance between the two tubes is no greater than 5/16", and the distance between the rear tube and the jacks behind it is 1/4", so certain tube rings and other tube treatments might not fit. 

Q: I assume that tubes are more sensitive to vibration than the Sig 30, any recommendations for isolation or vibration control?

The Isabella (as well as the RWA amps) is NOT very sensitive to vibration.  Feel free to try different vibration tweaks and racks, but they sound fanstastic even stacked on each other! 

Q: What else should a newbie to tubes know about the Isabella to get the best sound and longest life out of the unit???

Just sit back and enjoy it!  If you want to try some NOS tubes, I think you'll have fun and they do make a difference - but the Isabella still sounds great with the stock tubes.

Hmmm...

Being battery operated, I was kinda hoping the RWA gear would be more immune to the vibration / isolation considerations. And with such a small footprint it would seem a shame not to be able to just stack em and save space rather than have to space them out in a rack.

Did it really make that big a difference? I suppose side by side might be another option.

Hi Kitten,

Yes, you can stack them (I recommend putting the Isabella on the top) - they sound just fine like this, and you can even try using small cones between the units stacked, and under the bottom unit. 

Best regards,

Vinnie

[Mariusz]

Not quite.
.......there is at least 4-5 different kinds for 6922 tubes along.


Mariusz

I could only find one other version, for guitar amps? Where did you find the various different HAL tube damper versions of the 6922 size?
Bruno

I got mine from  John of Audio Connections N.J -  those are both new designs. No.....they do not look that much different then the previous models however, some improvements were made to rubber dumpers. Now their burn-in problems (with dumpers) were solved.......so I am told. Ring color on one is typical silver metallic and other is black. My buddy got some with dumpers made out of cooper or similar material. He likes those a lot but tubes with high microphonics benefit more with "original" rubber/silicon dumpers. Placement of rings also change the sound a bit. Try the top section first (about 3/4 to 4/5  of the tube length).
Your best bet is to call John for recommendations.

Mariusz

[Mariusz]

Hello Vinnie

I just want to say that Isabella on top of Sig.30.2 looks very , very cool.
If isolation between the two present some concerns , I would suggest a simple solution:
Two pieces of 3/4 inch MDF (sandwiched) or Butcher block  with set of spike + spike-discs (with adhesive).  Paint it in satin black..........Beautiful.
Just an idea. Maple blocks could replace spikes or cones if you are concern with damaging the finish.  I agree with Vinnie - Isabella on top. Better air flow and access to tubes if needed.

Mariusz