Considering Steremour II

Mucker · 24929

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Offline Mucker

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on: November 13, 2023, 03:22:53 PM
I have been using a very powerful Emotiva XPA-2 Gen 2 stereo power amp to drive high efficiency Klipsch RF-7II speakers:

Frequency Response 30Hz-24KHz ± 3dB
Power Handling 250W RMS / 1000W Peak
Sensitivity 101dB @ 2.83V / 1m
Nominal Impedance 8 ohms compatible
High Frequency Horn 8” square 90° x 60° Tractrix® Horn
High Frequency Drivers 1.75” (4.45cm) Titanium diaphragm compression driver
Crossover Frequency 1200Hz
Low Refequency Drivers Two 10” (25.4cm) Cerametallic™ cone woofers
Inputs Dual binding posts / bi-wire / bi-amp
Enclosure Type Bass-reflex via dual rear-firing ports
Height 48.5” (123.3cm) with feet
Width 11.6” (29.5cm)
Depth 16.3” (41.5cm) with grille
Weight 87.1lbs (39.5kg)

I have no plans to change from these speakers but recently tried my S3X amp with them and was very happy with how it drives them.

My dilemma now is that I am really wondering how much better a Stereomour II would drive the Klipsch. From a volume standpoint, I don't need much more than the S3X provides. However, I would desire possibly a bit more weight in the sound, particularly with the bass. A few more dB power with slightly more bass would really nail my needs. Cost does come into play and I want to make sure the jump to Stereomour will get me to where I want to be. Any comments, and or suggestions, is greatly appreciated.

I have never heard a 2A3 or 300B amplifier before but would like to experience one if the leap is big enough. Thank you!



Offline Doc B.

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Reply #1 on: November 13, 2023, 04:02:59 PM
The Stereomour might get you a little more bass weight than a S.E.X. amp, but the 2A3 is not a super weighty tube. The Kaiju would do more of what you are looking for. You could use the S.E.X. amp as a preamp to drive it.

Dan "Doc B." Schmalle
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Bottlehead Corp.


Offline Mucker

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Reply #2 on: November 13, 2023, 04:38:06 PM
OK Doc, thank you for the feedback. Appreciated.

If using the S3X as a preamp, is it done from the headphone jack?

I am currently using a Topping E70V DAC @ 2.5V out of RCA into S3X.

The E70V can output 5V from it's balanced XLR.

EDIT: I didn't realize Kaiju was a power amp., but after looking at it, I will certainly be considering it. Thank you. And I also have a Moreplay which I assume would work great with Kaiju?
« Last Edit: November 13, 2023, 06:32:48 PM by Mucker »



Offline Cary

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Reply #3 on: November 14, 2023, 05:18:31 AM
Since you are looking for a little more weight in the sound, you might to look into adding the Moreplay preamp.



Offline Doc B.

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Reply #4 on: November 14, 2023, 05:31:33 AM
Yup, Moreplay works great with a Kaiju.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Mucker

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Reply #5 on: November 14, 2023, 07:26:48 AM
Thanks!



Offline Mucker

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Reply #6 on: November 24, 2023, 08:21:36 AM
Ordered the Stereomour + Shunt + DC. Thanks for the sale price Doc!

Plan is to use the Moreplay as a pre-amp to it. I am using the Moreplay to feed S3X now and into speakers and it's really good.

I read an earlier post about turning the volume on the Stereomour to max and controlling with the Moreplay. I've done this with the S3X and have also used a combo of different volume positions on both. Is there a technically optimal way for volume setting? Will the tubes output better at higher or lower volume on one device over the other?

With my solid state DAC's I always have the output at 0dB (max) when running into an amp with a volume control.

Anyway, thanks again. I am really looking forward to building and operating the Stereomour.
« Last Edit: November 24, 2023, 08:26:48 AM by Mucker »



Offline Paul Birkeland

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Reply #7 on: November 25, 2023, 07:56:41 AM
With the volume pot all the way up and the balance pot centered, you will end up getting the best frequency response and the Stereomour is essentially operating as a power amp. 

If you take the wire leaving the wiper (middle lug) of each level of the balance pot and move it over a terminal to where the 33K resistor lands on the balance pot, that takes the balance control out of the circuit and gives you true power amp type operation when the volume pot is turned all the way up. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Mucker

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Reply #8 on: November 25, 2023, 08:51:33 AM
Ah interesting. I will definitely do that and will come back here when I am ready to do that. Thank you Paul.



Offline Mucker

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Reply #9 on: November 27, 2023, 08:34:47 AM
Hi Paul,

I ordered the MourQuiet today (thinking of the future and possibly wanting to use the amp as an integrated one), so I guess that means just running the Stereomour at max volume with Moreplay? Thank you!



Offline Paul Birkeland

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Reply #10 on: November 27, 2023, 02:18:30 PM
Yes, that's a good plan. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline rockdoc

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Reply #11 on: December 03, 2023, 06:46:18 PM
I can't say enough about the subs I built; the "Bucket Subs". Very inexpensive to put together. With the various high efficiency speakers I've used them with, they really help immensely with bottom end weight. Using a 300 watt class d plate amp on the speaker outputs with my various amps. Something to consider...

Steve T



Offline Mucker

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Reply #12 on: December 04, 2023, 11:05:24 AM
Thanks for the feedback Steve! My Klipsch RF-7ii are rated 30Hz-24KHz ± 3dB. They do a really good job with all but the lowest bass frequency.

I have a pair of SVS PB-12NSD that are superb with music that extend linearly into deep territory. They were unreal with home theater too.

I did integrate them with the Klipsch speakers using Moreplay and a power amp but found that I was enjoying the speakers without the subs just as much. And hence what set me on the path to the Stereomour.

My interests have changed away from home theater and into stereo music listening. My days of thunder are being put to bed and now I enjoy the lower volume warmth and clarity. I clearly prefer tube amp listening and heavily use my Crack and SEX amplifiers. Using the SEX as a speaker amp was a revelation into just how little power is needed for wonderful full audio.

After more listening with the SEX/Klipsch setup, the bass was certainly not lacking. Maybe just a whisker shy with weight but far from being an issue. Everyone has been talking about the Harman curve in the headphone and IEM circles, but my personal opinion is that Harman bass is too much.

Anyway, I think I am going to be very pleased with Stereomour as I already am with the S3X.



Offline Mucker

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Reply #13 on: December 18, 2023, 03:07:52 PM
Stereomour II + Shunt + DC filament + Mourquiet has arrived. Thanks for the quick shipping!

Assuming all together stock first; and then what order is now recommended? Thank you!



Offline Paul Birkeland

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Reply #14 on: December 18, 2023, 05:27:48 PM
Definitely the basic build first and let it run for a week.  The DC filament supply is the easiest to install and easiest to debug.  Then I'd go with the attenuator upgrade, and lastly the shunt regulator.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man