Erm.. Build the other channel of your F6 lashup.
Then connect the Nirvana speakers you claim to have ??
Post the subsequent impressions/results.
That would at least give a known quantity reference point.
Reads like you are using bin finds and complaining about getting Odd results...
MY initial fire up of My F6 build was disheartening.. at first attempt.
Turned out My long in service George Wright tube pre was the root cause.
Fitting a simple 10K pot betwixt my CDP and my new F6 was a Massive improvement.
Exquisite sounds is the best descriptor.. and with my 90/94 db (depends on what one reads) speakers,
I'm actually afraid to crank the volume to max.. they get that loud.
Then connect the Nirvana speakers you claim to have ??
Post the subsequent impressions/results.
That would at least give a known quantity reference point.
Reads like you are using bin finds and complaining about getting Odd results...
MY initial fire up of My F6 build was disheartening.. at first attempt.
Turned out My long in service George Wright tube pre was the root cause.
Fitting a simple 10K pot betwixt my CDP and my new F6 was a Massive improvement.
Exquisite sounds is the best descriptor.. and with my 90/94 db (depends on what one reads) speakers,
I'm actually afraid to crank the volume to max.. they get that loud.
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It's an easy matter to modify a linear pot to give good approximation of log law. ESP - A Better Volume Control
Thanks for the reminder. I'd forgotten that.
There isn't a very good selection of ganged linear pots (at Digikey, anyway) either.
I was told that something 5K or less was needed at either end of the BOSOZ to avoid poor results with impedance matching...a topic I understand poorly.
The Elliott pre uses a 100k (linear taper) gang pot, which I have in the parts bin here, and which is readily available.
Erm.. Build the other channel of your F6 lashup.
Then connect the Nirvana speakers you claim to have ??
Reads like you are using bin finds and complaining about getting Odd results...
I detect that good old non-judgemental attitude from the 'Mother country'.
complaining about getting Odd results...
I didn't complain of anything of the sort. I complained about lack of volume without a preamp between a line source and the Pass amp. As helpful people pointed out, I hadn't read or understood the gain spec on the F6, and hadn't realized that it was not a 'typical' 25W output power amp that could happily drive speakers with only an attenuator after a line source. And the general consensus here -not just from Zen Mod- was that a preamp with 5-10dB gain was called for to get the best performance from the F6.
Which I have built...
Glad to hear it works for you. I got a 'tsk tsk' about impedance problems when I suggested a 10k attenuator.
Well, first off, it would only be my 'claimed results'......
No matter which speakers I specify (and I have several from which to choose) I'm sure there would be comments that there was a 'quality' problem with my choice.
Then again, what is a 'comfortable' listening level for me may well be 'painfully loud' or 'too quiet to hear the musical detail' for somebody else.
Also, I'm not about to connect any valuable speakers to an amp that doesn't have some sort of protection from DC frying the voice coils, or to a build that's still at the breadboard stage.
25 watts per channel output power is a LOT. It definitely shouldn't need very sensitive speakers for ordinary listening. I'm confident that with the appropriate preamp and attenuator, the F6 will work with whatever speakers I choose.
Thanks for that suggestion.
I think they are more UK/Eurozone ?
I checked at Mouser (the other big parts place here) and they do carry the 5k linear 2-gang Alpha pots which are pretty basic but at least are available as:
-full size
-panel mount
etc... and at a reasonable price
I'm not sure the tolerance/tracking specs are that great, but I might not notice anyway.
Most of the choices I find are little plastic pots for PCB mounting, which may have great elements but are not really practicable for the sort of builds I do ....(once I get to the stage of actually 'approving' a build to deserve a proper chassis & case!
).
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I'm a nubs as well and I've been reading trough this thread daily with interest as I'm finally beginning my Aleph J build. I've assembled the power supply, and purchased and assembled the dc speaker protection kit as well. The topic of amp gain is also something that I've wondered about with my build, and I'm trying to understand it as well. The Aleph J manual states that it requires 1.5 volts input for the rated 25watt output. In the Aleph J's case, would a CD player with a rated output of 2V +/- 0.5 as stated in the players manual be sufficient to drive the Aleph to its stated output. Papa has mentioned his measurements are always stated as rms. My CD player for reference is a Yamaha CDX-470.
Good question, and very well stated...
You won't be surprised that I'll not venture an answer for you but I'm hopeful that some of the people who have been helping with my education here will help you as well.
EDIT: I can't resist....
Since the Aleph J has a published gain of 20dB, vs. the F6's 14 dB, you should be much closer to having enough drive from your CDP than I was with my F6.
The preamp recommendations I got were for something in the 5-10dB range.
Also, I'm glad that somebody else may learn from the efforts to reduce my confusion!
You won't be surprised that I'll not venture an answer for you
but I'm hopeful that some of the people who have been helping with my education here will help you as well.EDIT: I can't resist....
Since the Aleph J has a published gain of 20dB, vs. the F6's 14 dB, you should be much closer to having enough drive from your CDP than I was with my F6.
The preamp recommendations I got were for something in the 5-10dB range.
Also, I'm glad that somebody else may learn from the efforts to reduce my confusion!
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Have you actually measured the output of your cd player?
One way to do it is put a music CD in the player set Persistence on your oscilloscope to Infinite, load the player with a suitable resistive load, say 50k to 100k, play one full music track on the CD and see what the peak out put of the CD is.
One way to do it is put a music CD in the player set Persistence on your oscilloscope to Infinite, load the player with a suitable resistive load, say 50k to 100k, play one full music track on the CD and see what the peak out put of the CD is.
test CD with 1K sine @ 0db is perfect tool for measurement of CD player output
even better , when decent DVM is good enough ( no need for scope) - same CD with 400-500Hz 0db sine
while testing , it's best to disconnect it from any amplification downstream ...... to avoid pain in the ...... ears
even better , when decent DVM is good enough ( no need for scope) - same CD with 400-500Hz 0db sine
while testing , it's best to disconnect it from any amplification downstream ...... to avoid pain in the ...... ears
Hi 2 Pico, I unfortunately don't have that type of equipment, nor do I know anyone who does. I'm just getting into building audio equipment, driven mostly by my love of music, quality sound reproduction, and to satisfy the tinkering part of my personality. I'm learning as I go, and reading to try and understand as much as I can. I do realize my question has a "hypothetical" aspect to it because of all the variables with how different manufacturers state measurements, and therefore an absolute Yes or No isn't possible. Other than me "trying and finding out" when my build is done, I was curious what a general thought would be.
I'm actually interested to see what his music cds output, not a certified test cd, although the test cd will confirm engineering spec of cd player.
Most fairly modern oscilloscopes have this feature, if you can't get hold of one, just do as zen mod suggests with a decent wide bandwidth multimeter.
Most fairly modern oscilloscopes have this feature, if you can't get hold of one, just do as zen mod suggests with a decent wide bandwidth multimeter.
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Please let me know when you find one (a free one, preferably
).I looked but had no luck - most of the 'test' CDs were the 'audiophile' kind, not 'engineering' style.
I'm looking for an ISO file to burn, or equivalent.....
I guess you can look for a test tone generator. There are a also a few test tones
here:
http://www.diyaudio.com/forums/mult...much-voltage-power-do-your-speakers-need.html
Dennis
here:
http://www.diyaudio.com/forums/mult...much-voltage-power-do-your-speakers-need.html
Dennis
Thanks for that explanation and ideas, Pico and ZM.
I guess I'd need a newer digital scope? My HP54501 is the newest 'tech' I have and it can get some data like this, but there's no
'Infinite Persistence' setting that I can find.
Is there a list of CD players that have actually been tested this way (playing a music recording and watching the output with a scope), here at diyaudio (or anywhere)?
The preliminary numbers I got were quickly interpreted as 'defective CDP' .....which may be possible but I never noticed any difference between that 'shop' Sony CDP and the 'good' Rotel CDP when they were both in the 'main setup'.
Thanks, Dennis.
I don't completely understand how the mp3 tones available for download there, compare in 'loudness' with actual music levels from CDs. Also, I'm not completely confident that if I burn an mp3 to CD that I'll get the same result as if somebody else does the same thing with their computer setup. (I recall running across 'normalize volume' settings in some software advanced options...but I may be mis-remembering.
) But it seemed like an interesting test. I thought it strange that several people said the music was very loud but the test tones weren't.And, which is more important/valid - the level measured across the actual amplifier input or across a 50-100k resistor? Or, is there not a difference?
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