[Portos]

Hi there,

I’m considering the SWL9.0 SE to partner with the RWA Sig 30.2 and M&D Sapphire speakers (fed by a Benchmark DAC1).  I might also go crazy, skip the 9.0, and go directly to the 36.5   aa.  . . probably save money in the long run.

Anyway, before making the final decision, I had a few questions I was hoping you could help me with:

1. Heat.  I would place the preamp on a shelf closed on 3 sides (wood on the sides, glass on the front – yes, I have children).  The back is completely open, about 3 inches from the wall.  I can clear 3 inches above the top of the preamp, and 1.5 on each side.  Is this enough ventilation?  Does the 36.5 dissipate heat more efficiently than the 9.0 due to the heavier enclosure?

2. HT/BP. I read in another post that the 36.5 does not need to be turned on for the pass-through to work.  Is this the case for the 9.0SE too?

3. Operating time.  The pre-amp would serve double duty, being used by my family during the day and by me at night.  I would expect it to be turned on 16 hours a day, 7 days a week.

Is this OK?  I’m fine with replacing tubes every 1 to 2 years.  I’m more worried about capacitors and the rest of the circuit degrading quickly with this kind of use and abuse.  This is partially where I come from with the heat generation question.

4. Listening at low volumes.  I listen mostly at night.  Do the qualities of these preamps come through just as well at low volumes as with less attenuation?  Is this a distinguishing factor b/w the 9.0 and 36.5?

Thank you all for considering these questions. 

Paul

[low.pfile]

Welcome to AC!


Wow you've given yourself a challenge given the environmental constraints (impact on tube gear) and extended use time (SLA powered amp).

I am curious to the answers myself from Dan. Well, I do know the 9.0 SE needs to be powered on for HT/BP.

I have been breaking in my RWA 30.2 and turn it on in the morning -- the level is about 65-70dbs(metered) and then listen to it through the evening after I get home from work. so new it seems to run at least 14 hours on the charge.

cheers

[modwright]

1. Heat.  I would place the preamp on a shelf closed on 3 sides (wood on the sides, glass on the front – yes, I have children).  The back is completely open, about 3 inches from the wall.  I can clear 3 inches above the top of the preamp, and 1.5 on each side.  Is this enough ventilation?  Does the 36.5 dissipate heat more efficiently than the 9.0 due to the heavier enclosure?
It will run a bit warm and I typically do not advise using any tube gear in such an enclosed rack.
2. HT/BP. I read in another post that the 36.5 does not need to be turned on for the pass-through to work.  Is this the case for the 9.0SE too?

3. Operating time.  The pre-amp would serve double duty, being used by my family during the day and by me at night.  I would expect it to be turned on 16 hours a day, 7 days a week.
No problem except that you will be re-tubing sooner and again the heat IS an issue in an enclosed cabeinet.

Is this OK?  I’m fine with replacing tubes every 1 to 2 years.  I’m more worried about capacitors and the rest of the circuit degrading quickly with this kind of use and abuse.  This is partially where I come from with the heat generation question.
If you had a small fan or something in the cabinet, this would keep the environment cooler.  The unit does not get exremely hot, but the tubes do give off heat and if left in an enclosed space, the overall temp will increase to the point that it could shorten the life of some components.  There are VERY few electrolytic capacitors in the unit as most are our own custom Teflon and poly film/foil design.

4. Listening at low volumes.  I listen mostly at night.  Do the qualities of these preamps come through just as well at low volumes as with less attenuation?  Is this a distinguishing factor b/w the 9.0 and 36.5?
The LS 36.5 has lower overall gain and will thus operate better at lower volumes.  It is also quieter.

I hope this helps and I apologize for the tardy reply.

Thanks,

Dan W.