[steve f]

Dave, That's a new preamp brand for me. Can you provide any info? And yes I agree with you that there is good stuff out there that is competitive with the "best" and affordable for a lot more music lovers.





Steve

[a.wayne]

Well, I can't seem to see any numbers for output impedance anywhere, other than for the headphone jack.  Plus it's a kit and it's $1000 including tubes and resale value will be very low because it's a kit and because it is very homemade looking.   With power amplifiers you are better leaving the power amp on 24/7 and I wouldn't do that with a tube preamp so that would mean (for me) having to switch the power amp off before the preamp (good practice to avoid power switch noise).  Also the power amp should be off before turning the preamp on again.  So you will need warm-up for both.  If you want a tube pre I would go with a popular make that has excellent build quality, resale value and looks.  Like used Audio Research, Sonic Frontiers, C-J, Quicksilver, etc.  But beware output impedance issues!

Frankly I think you would be better off with a solid state Headphone amp/pre with balanced outputs and leave it on all the time, along with the power amp.  Like a Benchmark, Bryston, Wyred 4 Sound, etc.

On the crown you can always turn the input gain to zero and turn pre off , you will be hard pressed to beat a GOOD tooby pre with an  SS pre-amp .... So i can understand sticking with one ....


Regards

[DaveC113]

Sure, the Aikido is John Broski's design, here's his store:

http://glass-ware.stores.yahoo.net/index.html

I also use it as the drive stage for a pair of EL34s run in single ended triode mode, it makes for a great drive stage, much better than a typical single triode, even with a CCS load. It has enough gain for my system (barely) but a 6SL7 would make for a more normal amount of gain. The preamp/SET combo only has about 15 dB gain total, the preamp is 20 dB with 6SN7s. The amp is -5 dB because of the OPTs.

I compared my Aikido/EL34 SET to an Air Tight Pre / Fi 2a3 monoblock combination on Lamhorns and it resulted in the sale of the 2a3 amps... 

noway, usually you do want the amp off when the preamp is turned on or off but the last couple tube pres I've had, including my Aikido, does not produce a spike on turn on/off so it's not strictly necessary. You could test by turning the gain on the Crown way down and see if there's a spike. Looks like a.wayne beat me to it... 

[JDUBS]

I guess I'm confused with worrying all that much about a tube pre ahead of this thing when the signals just getting converted to digital and then back to analog.

-Jim

[steve f]

I'm not sure I understand it all either. Yes, the crossover appears to operate in the digital domain, but what about when crossover functions aren't used? I've been enjoying my XLS amps in "bypass" mode. So far, I haven't tried any of the available features.

Steve

[JDUBS]

I'm not sure I understand it all either. Yes, the crossover appears to operate in the digital domain, but what about when crossover functions aren't used? I've been enjoying my XLS amps in "bypass" mode. So far, I haven't tried any of the available features.

Steve

I'd love to know if bypass modes goes around the unit's dsp altogether.  I'll ask the Crown techs.

-Jim

[steve f]

The owners manual doesn't discuss bypass or monoblock when selected, the limiters are digital, but can be defeated. I look forward to what the Crown techs have to say.

Steve

[guest61169]

...Output impedance is only 15 Ohms....

That's not from the line outputs.  I bet it is in the high hundreds or low to mid thousands like most tube preamps.   And it changes with frequency.

...

noway, usually you do want the amp off when the preamp is turned on or off but the last couple tube pres I've had, including my Aikido, does not produce a spike on turn on/off so it's not strictly necessary. You could test by turning the gain on the Crown way down and see if there's a spike. Looks like a.wayne beat me to it... 

That might work depending on the preamp.  It goes against conventional wisdom but if it works it works.  Maybe just try it first with a cheap pair of speakers instead of expensive ones.

[steve f]

@noway. You are  mistaken. 15 Ohms is the correct number. It isn't posted on the spec sheet, but is mentioned  by the  designer in the forum pages concerning the preamp.

Steve

Edit: first post on  New product! Etc thread.

[guest61169]

@noway. You are  mistaken. 15 Ohms is the correct number. It isn't posted on the spec sheet, but is mentioned  by the  designer in the forum pages concerning the preamp.

Steve

Edit: first post on  New product! Etc thread.

OK.  I'll see if I can find that.  Do you have a link?  I might even consider a tube pre if there is one that low.

[steve f]

My iPad sucks at posting links. Just go to the Transcendent Sound website forum. It's the first post of the second topic.

Steve

[guest61169]

Wow.  I just saw that.  That's a crazy low number he's quoting.  I'll have to look into that if I ever switch to a tube pre.

[Alan]

Crown's website is acting funny. Any news from CES? See if this works...
http://www.crownaudio.com/row/amplifiers.html

[OzarkTom]

Crown's website is acting funny. Any news from CES? See if this works...
http://www.crownaudio.com/row/amplifiers.html

I am certain that this is the website to watch for news from the CES show. Harman is introducing some new Revel speakers and a new Levinson amp.

http://news.harman.com/content/default.aspx?NewsAreaId=2

[JDUBS]

The owners manual doesn't discuss bypass or monoblock when selected, the limiters are digital, but can be defeated. I look forward to what the Crown techs have to say.

Steve

I asked about the conversion of the A->D and the D->A as well as if the DSP is bypass-able.  This is the response I got:

"The sampling rate is 48 kHz and is taking 24 bit samples. The conversion still takes place in Stereo Bypass mode."


That REALLY sucks!  I wouldn't bother spending big bucks on anything before this amp if its just going to get converted to digital and back to analog.

-Jim

[rodge827]

Very interesting...I will try to borrow a quality tube preamp from a friend for comparison before I do anything different than how I'm currently set up.

Thanks for the post.

[DaveC113]

That REALLY sucks!  I wouldn't bother spending big bucks on anything before this amp if its just going to get converted to digital and back to analog.

-Jim

I disagree, and it's also possible the signal does not go D > A either. The amp is clean enough that it can resolve a good source.

[JDUBS]

it's also possible the signal does not go D > A either

What do you mean?  I asked the Crown guys this specifically. 

-Jim

[steve f]

A 48K sampling rate with a 24 bit rate is something my cats can't hear, let alone me. I do get the purist approach though. The amps performance may be unaffected by conversion. We need a digital engineering guru to join in.

[srb]

A 48K sampling rate with a 24 bit rate is something my cats can't hear, let alone me.

A 48KHz sampling rate can reproduce frequencies up to 24KHz.  Cats can hear up to 79KHz and dogs up to 44KHz. 

Of course, not the point at all, but some of the same people who think this amplifier possesses some magic and 95% of the sound of much more expensive amplifiers with analog-only signal path also wouldn't even consider an Apple TV that resamples to 48KHz with no additional AD/DA conversion.

Interesting.

Steve