Update
A few days burn in and everithing I can happily say is very stable
Final biasing is 500mv - with under 2mv offset.
Did those adjustments with the lid on to balance temperatures and make sure it wasnt doing anything naughty
Listening review of the First Watt F6 ( upgraded from the F5 )
Pre - Nakamichi CA5
Source - Cyrus CD8 SE
Medium - CD
Speakers - Klipsch La Scala ( Modified )
Sensitivity min 104db
Album - Pink Floyd - Dark Side Of The Moon
Warm up 45 min / 1 hour
General - Laid back and full of natural detail in all areas
Treble - is in its place without shouting and high notes hold in the air a longer time however I believe this will get better with a little more burn in time
Mid - very listenable and exact ( not clinical ) with a surround feel to it ( it's both exact and raw at the same time )
Bass - is extended slightly more than the F5 however it has a better tighter multi layer bass presentation with lots of inaudible bass vibration felt even at low volume
Totally enjoyable - let's look for another CD to play
And to surmise overall performance
I feel that the amp it will need a little more burn in time to hear it's full potential
It's also different to the F5 so my ears need to adjust to it as well
The F5 is more forceful but in a nice way
The F6 is more exact but more analogue in nature
As time went on I also had to adjust the db attenuation on the XOver to find the sweet spot synergy in my system
Those XOver attenuator adjustments were-
Tweeter had to go down ( softer ) @ -7 db
Mids had to go higher ( louder ) @ 9db tap wire
May need to play with it a bit more but that just confirms that the bass is more forceful on the F6 at the old F5 setting
Should give it a week or more to settle in and burn in but it's sounding good at present
Another observation with bass
I was holding the iPad in one hand
As I walked closer the the system and speakers to adjust volume it started vibrating in my hand and I mean strong vibrations from the lower inaudible bass
Will report back again if members want me to
Cheers
FR
A few days burn in and everithing I can happily say is very stable
Final biasing is 500mv - with under 2mv offset.
Did those adjustments with the lid on to balance temperatures and make sure it wasnt doing anything naughty
Listening review of the First Watt F6 ( upgraded from the F5 )
Pre - Nakamichi CA5
Source - Cyrus CD8 SE
Medium - CD
Speakers - Klipsch La Scala ( Modified )
Sensitivity min 104db
Album - Pink Floyd - Dark Side Of The Moon
Warm up 45 min / 1 hour
General - Laid back and full of natural detail in all areas
Treble - is in its place without shouting and high notes hold in the air a longer time however I believe this will get better with a little more burn in time
Mid - very listenable and exact ( not clinical ) with a surround feel to it ( it's both exact and raw at the same time )
Bass - is extended slightly more than the F5 however it has a better tighter multi layer bass presentation with lots of inaudible bass vibration felt even at low volume
Totally enjoyable - let's look for another CD to play
And to surmise overall performance
I feel that the amp it will need a little more burn in time to hear it's full potential
It's also different to the F5 so my ears need to adjust to it as well
The F5 is more forceful but in a nice way
The F6 is more exact but more analogue in nature
As time went on I also had to adjust the db attenuation on the XOver to find the sweet spot synergy in my system
Those XOver attenuator adjustments were-
Tweeter had to go down ( softer ) @ -7 db
Mids had to go higher ( louder ) @ 9db tap wire
May need to play with it a bit more but that just confirms that the bass is more forceful on the F6 at the old F5 setting
Should give it a week or more to settle in and burn in but it's sounding good at present
Another observation with bass
I was holding the iPad in one hand
As I walked closer the the system and speakers to adjust volume it started vibrating in my hand and I mean strong vibrations from the lower inaudible bass
Will report back again if members want me to
Cheers
FR
I am using a tube preamp that has a 12AU7 tube for the gain and it is one I built. I like a tube pre with SS amps with my horn speakers. With conventional speakers I do not think it would matter that much if a good SS pre was used.
Interesting, do you know the output impedance? ( of your pre) If higher than normal, like many tube preamps, does it "soften the highs" as a few were talking about on the F-6 thread? (not the build thread)
Full Range, do you know the output impedance of you Nakamichi Preamp? Did you notice "softened highs" being a problem. I ask as I was planing on useing BA-3 FE which is over 1K...I did note you said something about having to turn down tweeter on your crossover...
Just found it...appears to be 1K.
http://akdatabase.org/AKview/albums/userpics/10007/Nakamichi CA-5 User Manual.pdf
Russellc
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My output impedance varies with the pot but normally it is around 10K which is high but I do not think the highs are soft but I do not hear above 11K hz anyway being 66 years old. The highs I hear sound great.
Well, I just turned 60 so I am not far behind! I feel better about the BA-3 preamp now, we will see.
Russellc
I have built a BA-3 preamp and it is a nice SS preamp but remember I have horn speakers and I prefer a tube preamp. I do not exactly know how to describe it in words but I just like the a tube preamp with a SS amp and there are others like me as well. Maybe I just like a little more 2nd harmonic. The sound is smoother is one way to describe it, not so analytical. With rock and roll or other modern music the SS preamp would probably be best but my listening habits now are more jazz and blues.
I know what you mean, I have a set of Altec horn speakers (A-7 ) as well as a large set of Econowaves, and two tube preamps. I used to be All tubes until I started building this Pass stuff. I actually sold my Mcintosh MC225 after completing the F-5....I swore I would never let it go! Still have tube power amps and a Mcintosh MR 67 tuner. Yes, I used the tube preamp with my F-5, didnt care for it with B-1, except with the High efficiency horns, and I still like the tube pre better, but have come to really like the BA-3. We could probably both use a distortion analyzer to crank more second order on the BA-3!
Have you tried the BA-3 Pre with the F-6, or if you would when you get time and tell me what you think.
Thanks,
Russellc
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That is the way I first used my F6 with the BA-3 pre and the B1 which I also have. I think it boils down to personal preference more than anything else. Both the BA-3 and B1 sounded great it is just I prefer a tube pre. I am intrigued with the Luminaria using SIT's but the SIT's are unattainable now as it is designed.
If you want to make a preamp with lu1014d I'll be happy to sell you some to get the job done.
Thanks for the offer but I already have some. I bought them thinking of building the F3 but then the SIT amp designs came out and I am sitting on some of them too. I really like the sound of my F6 with my tube pre with triode tubes.
Nice preamp. I look forward to hearing your impressions with the tube preamp and horns.
The next review @wdecho 
You will all remember on the last occasion my review was the F6 connected to the Nakamichi pre amp
This time the F6 is connected to my one of a kind custom valve pre amp with a twist? - you see its also a DAC with an OEM TDA 1541 chip
Made by Earle Weston in Australia - sb343971 - Home
In a nutshell it is a Tube pre-amplifier running a directly coupled 6SN7 driving an output transformer with a OEM TDA1541 DAC board on one of the 4 selectable inputs.
The pre-amplifier acting as a gain stage and buffer for the DAC.
It runs three RCA inputs, then the digital section with momentary toggle switch and LED's that allow you cycle through USB, Optical, SPDIF and I2S inputs.
Specs on the tube section are
Distortion at full volume > 0.06%.
Frequency response +/- 0.25db 20hz to 50khz.
Signal to noise ratio >90db.
Hum at zero volume 0.15 millivolt.
Output impedance 80 ohms.
OK now that's out of the way I can start on the review
Over a week of burn in and everything is very rock solid and stable
Final biasing checked and steady on 500mv
Listening review of the First Watt F6 ( upgraded from the F5 )
Tube 6SN7 pre-amp ( see specs above )
Source - Cyrus CD8 SE
Connected to the TDA 1541 on the pre via coax cable
Medium - CD
Speakers - Klipsch La Scala ( Modified )
Sensitivity min 104db
Album - Pink Floyd - Dark Side Of The Moon and Test CD compilation
Warm up - 1 hour
General - Not as forceful as the Nakamichi pre but is fuller,
lets just say its the difference between full cream milk and fat free milk
Treble - Is very smooth and has a crisp haunting feel, and high notes still hold in the air for a long time
Mid - Is very exact but a little more meat in the music, with an enveloping feel to it (again it's both exact and full at the same time )
Bass - Surprisingly has remained tight with multi layer bass presentation the inaudible bass vibration is still felt even at low volume, however at a slight loss of extended bass range but still totally nice
And to surmise overall performance
I feel that the amp needed more break-in since the last test and that's what it got, a lot of burn-in time. and its worked its magic
The F6 connected to the tube pre-amp and TDA 1541 DAC is equally exact but more analogue and full cream milk in nature
I also ran my test track CD and was totally immersed in the music
Cheers
FR
You will all remember on the last occasion my review was the F6 connected to the Nakamichi pre amp
This time the F6 is connected to my one of a kind custom valve pre amp with a twist? - you see its also a DAC with an OEM TDA 1541 chip
Made by Earle Weston in Australia - sb343971 - Home
In a nutshell it is a Tube pre-amplifier running a directly coupled 6SN7 driving an output transformer with a OEM TDA1541 DAC board on one of the 4 selectable inputs.
The pre-amplifier acting as a gain stage and buffer for the DAC.
It runs three RCA inputs, then the digital section with momentary toggle switch and LED's that allow you cycle through USB, Optical, SPDIF and I2S inputs.
Specs on the tube section are
Distortion at full volume > 0.06%.
Frequency response +/- 0.25db 20hz to 50khz.
Signal to noise ratio >90db.
Hum at zero volume 0.15 millivolt.
Output impedance 80 ohms.
OK now that's out of the way I can start on the review
Over a week of burn in and everything is very rock solid and stable
Final biasing checked and steady on 500mv
Listening review of the First Watt F6 ( upgraded from the F5 )
Tube 6SN7 pre-amp ( see specs above )
Source - Cyrus CD8 SE
Connected to the TDA 1541 on the pre via coax cable
Medium - CD
Speakers - Klipsch La Scala ( Modified )
Sensitivity min 104db
Album - Pink Floyd - Dark Side Of The Moon and Test CD compilation
Warm up - 1 hour
General - Not as forceful as the Nakamichi pre but is fuller,
lets just say its the difference between full cream milk and fat free milk
Treble - Is very smooth and has a crisp haunting feel, and high notes still hold in the air for a long time
Mid - Is very exact but a little more meat in the music, with an enveloping feel to it (again it's both exact and full at the same time )
Bass - Surprisingly has remained tight with multi layer bass presentation the inaudible bass vibration is still felt even at low volume, however at a slight loss of extended bass range but still totally nice
And to surmise overall performance
I feel that the amp needed more break-in since the last test and that's what it got, a lot of burn-in time. and its worked its magic
The F6 connected to the tube pre-amp and TDA 1541 DAC is equally exact but more analogue and full cream milk in nature
I also ran my test track CD and was totally immersed in the music
Cheers
FR
I thought you may like it. There is absolutely nothing wrong with the sound using a good SS pre but to me the F6 sounds much better with a good tube pre or for that matter any SS amp. I would love to hear the Luminaria preamp with the SIT's to compare. This is with horn speakers, I do not know if there would be as much difference with conventional speakers.
Don't forget you can also tweak F6 for more 2nd harmonic after rerouting caps.
I need a schematic to peruse
Also, I should also mention that I don't have as much volume in the tube amp, with a good listening volume achieved @ 8 to 9 on the dial, and probably to much volume in the Nakamichi to have me thinking of a passive remote volume control for the Nak
Decisions decisions
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