Hi,
I can't realy reply to your specific request, but for whatever it is worth here is my experience...
I have proceeded yesterday to some listening tests around the B1K which is now included in a somewhat complex and flexible "switch unit" to enable various comparisons... on top of being my main preamp for my main HIFI.
The LS aren't 100dB/m/W: they are Klipsch advertised as 96dB/m/W. They are probably less efficient than advertised vs other manufacturers, but are indeed as advertised in my listening conditions / room when I measured them. Note real 100dB/m/W in anechoic chambers are very unusual as mags reviews revealed, but well.
Comparing on the fly together with a friend the B1K (that I tuned womewhat and adjusted with a "less sugar" bias) vs line direct (no preamp at all in the signal path, pure sound, something I consider perfection given the very low output impedance source can easily drive the power amp with short quality connecting cables without perceived dynamic loss):
In short, it is quiet and natural enough IMHO, and defo not an effect box. Note I don't suffer from tube ringing either.
The particularities in the sound we noticed yesterday were the following:
I am quite biased because I love this wonderfull unit, but on the other hand I like it pure LOL!
After 2 years I pondered a lot on what to do. Should I move the bias even more in direction "more neutrality", but then what's the point ending up with the sound I have already in direct modus? Shall I build another active preamp, more faithfull / true to the music, retaining the B1K excellent sonic abilties? Given I am not sure such thing exists, I will be completely honest: the difference listed above between my tuned B1K and direct modus are in terms of magnitude very small. Most people would probably not notice the differences (other than the additional flow and airyness, so enjoyable in long listening sessions) or potential negatives, so "air gets really very thin" for any other preamp "in between" and I concluded it was not my priority given the projects I have on hand LOL
At the end, I have my preamp-switch box (which enables me direct comparison to a third preamp should I wish it one day!) and use it most of the time in passive mode, mostly to save the tube's life and because it wouldn't add really anything to the listening experience on movies, cartoons (LOL) or at very low levels. Depending on personal mood, and on records, the ones that benefit from some drive and/or smoothness -typicaly RnB from the 70s- it will be looped in in my full range system to make life much better while not having any exagerate loudness or equalizer effect!
I recommend this unit as it is possibly faithfull enough to compete with any preamp while having that little enjoyable special extra that no absolute straight line pre seems to offer. That's to answer hopefully your questions.
Now, there is one big negative though: if you need gain in your chain coming from a preamp, then you would probably benefit from considering other options. Although the B1K saturated around 10V (been there by mistake switching a souce directly to it without any attenuation!) and survives the punishment astonishly well, you can't IMHO really use the B1K's 16.5dB gain. Reason being I find the B1K sounds fine up to 2V output, possibly still OK at 4V, but any higher output level is linked to exagerated harmonic distorsions to my ears. Yes, I like it not too sweet. So you won't really add gain in your chain given say a 2V source. Further, the sonic tricks the B1K performs on music are in a similar veine to my ears to the VFET (who probably blows and blurs less though), so I wouldn't want to add my (eventhough tuned to less sweet) B1K to say my VFET amp: too much of the same thing really, but I read here that opinions differ on that and if you like that particular sound signature to death, why not? After all, it is you choice and DIY! And I don't know how you perceive or rate your existing EL34 amp re sonic signature...
All IME
Sorry for another long post
Claude
I can't realy reply to your specific request, but for whatever it is worth here is my experience...
I have proceeded yesterday to some listening tests around the B1K which is now included in a somewhat complex and flexible "switch unit" to enable various comparisons... on top of being my main preamp for my main HIFI.
The LS aren't 100dB/m/W: they are Klipsch advertised as 96dB/m/W. They are probably less efficient than advertised vs other manufacturers, but are indeed as advertised in my listening conditions / room when I measured them. Note real 100dB/m/W in anechoic chambers are very unusual as mags reviews revealed, but well.
Comparing on the fly together with a friend the B1K (that I tuned womewhat and adjusted with a "less sugar" bias) vs line direct (no preamp at all in the signal path, pure sound, something I consider perfection given the very low output impedance source can easily drive the power amp with short quality connecting cables without perceived dynamic loss):
- I don't hear any additional noise coming from the B1K, whatever the volume position and having my ears at the LS (there is an extremly faint noise probably coming from the power amp whatever the set up when turning up the volume inconsiderably)
- My tuned B1K sounds very close and faithfull to the original sound... oddly though with some particularities (sounds contradictory, I know)
In short, it is quiet and natural enough IMHO, and defo not an effect box. Note I don't suffer from tube ringing either.
The particularities in the sound we noticed yesterday were the following:
- An ability to enhence space, air, 3D in the soundstage
- An ability to add PRAT to old or average records
- Somewhat more smoothness and natural flow, but without robbing any of the attack / rising rate edges... quite remarkable, can't explain it really
- An enjoyable somewhat magnifying effect... whatever the instrument or voice, the B1K seems to be able to make them easier to follow, without though exagerating them in whatever way, with more perceived details and articulation
- A slightly reinforced deep bass, very enjoyable on old records and possibly with small speakers, less so IMHO on excellent records with true full range speakers... for me a potentialy negative point worth considering
- On complex full range recordings (I love Verdi...), a marginaly less clear picture, a tad more confusion... while though retaining its positives
I am quite biased because I love this wonderfull unit, but on the other hand I like it pure LOL!
After 2 years I pondered a lot on what to do. Should I move the bias even more in direction "more neutrality", but then what's the point ending up with the sound I have already in direct modus? Shall I build another active preamp, more faithfull / true to the music, retaining the B1K excellent sonic abilties? Given I am not sure such thing exists, I will be completely honest: the difference listed above between my tuned B1K and direct modus are in terms of magnitude very small. Most people would probably not notice the differences (other than the additional flow and airyness, so enjoyable in long listening sessions) or potential negatives, so "air gets really very thin" for any other preamp "in between" and I concluded it was not my priority given the projects I have on hand LOL
At the end, I have my preamp-switch box (which enables me direct comparison to a third preamp should I wish it one day!) and use it most of the time in passive mode, mostly to save the tube's life and because it wouldn't add really anything to the listening experience on movies, cartoons (LOL) or at very low levels. Depending on personal mood, and on records, the ones that benefit from some drive and/or smoothness -typicaly RnB from the 70s- it will be looped in in my full range system to make life much better while not having any exagerate loudness or equalizer effect!
I recommend this unit as it is possibly faithfull enough to compete with any preamp while having that little enjoyable special extra that no absolute straight line pre seems to offer. That's to answer hopefully your questions.
Now, there is one big negative though: if you need gain in your chain coming from a preamp, then you would probably benefit from considering other options. Although the B1K saturated around 10V (been there by mistake switching a souce directly to it without any attenuation!) and survives the punishment astonishly well, you can't IMHO really use the B1K's 16.5dB gain. Reason being I find the B1K sounds fine up to 2V output, possibly still OK at 4V, but any higher output level is linked to exagerated harmonic distorsions to my ears. Yes, I like it not too sweet. So you won't really add gain in your chain given say a 2V source. Further, the sonic tricks the B1K performs on music are in a similar veine to my ears to the VFET (who probably blows and blurs less though), so I wouldn't want to add my (eventhough tuned to less sweet) B1K to say my VFET amp: too much of the same thing really, but I read here that opinions differ on that and if you like that particular sound signature to death, why not? After all, it is you choice and DIY! And I don't know how you perceive or rate your existing EL34 amp re sonic signature...
All IME
Sorry for another long post
Claude
It can get some hum when you turn it up well beyond what you would typically listen to. In any realistic situation, it is very quiet. A great sounding preamp. Relatively cheap when you are bringing tube power amps into the equation.
I don't have any links comparing it to expensive preamps but have done so in my house. The Korg is a special unit. It doesn't have the most reinforced bottom end when compared it's solid state counterparts. However, the mids and highs are syrup and honey and the bass is more than having no preamp. It is a pretty sounding little thing while still having lots of detail, great imaging, spacial detail etc.
Totally worth having in your arsonal. I like to switch preamps (I have 4) and the little Korg always brings a smile to my face. So it depends on what you want.
I recommend you get the SMPS filter from the DIYaudiostore as well as some film caps. I used wima PPP films. WIMA FKP .22 in the first location Wima FKP 1uf in the middle and as of now have 6.8uf clarity caps PX on the outputs.
The wima's are nice because they don't require any fiddling to get them to work with the holes that were used for the original electrolytic caps.
I don't have any links comparing it to expensive preamps but have done so in my house. The Korg is a special unit. It doesn't have the most reinforced bottom end when compared it's solid state counterparts. However, the mids and highs are syrup and honey and the bass is more than having no preamp. It is a pretty sounding little thing while still having lots of detail, great imaging, spacial detail etc.
Totally worth having in your arsonal. I like to switch preamps (I have 4) and the little Korg always brings a smile to my face. So it depends on what you want.
I recommend you get the SMPS filter from the DIYaudiostore as well as some film caps. I used wima PPP films. WIMA FKP .22 in the first location Wima FKP 1uf in the middle and as of now have 6.8uf clarity caps PX on the outputs.
The wima's are nice because they don't require any fiddling to get them to work with the holes that were used for the original electrolytic caps.
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Simple and cheap solution for sensitive nutubes. This one is for air motion sensitivity, if you have an open case that you don't wish to close. Costs about few $ to print out in material (my suggestion is resin, half abs like and half flex resin), and you can use double sided transparent rubber tape cut out to measure as it is 2mm thick wall (it sticks just enough not to make it hard to peel off when you need to replace the tube, and it's gummy enough to absorb vibrations). 3d model is in zip file.
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Does the SMPS filter from the DIYaudiostore have a big effect on a stock Korg B1 unit (with the stock walwart power supply)? I'm thinking of getting one and incorporating it into my build if there is a noticeable improvement.
I think so. I wasn't able to A/B test it with a stock unit but it certainly sounds very nice. It fits nicely off to the side so long as you use taller standoffs. It is cheap and takes about 20 minutes to put together once you have the soldering station going and the case opened up.
I drilled two holes as I thought that 4 weren't necessary. Lay the board down and drill your holes before you have the board populated. I installed it after the power switch.
I drilled two holes as I thought that 4 weren't necessary. Lay the board down and drill your holes before you have the board populated. I installed it after the power switch.
I made a plexi lid with some graphics that, though not as planned, turned out interesting.
It has had enough time to settle-in (the poly caps burned-in prior to the build) and I like it!
So much so that I had to listen to side 2 of Ziggy Stardust twice, b2b, something I never do, just because it sounded so d@#& good.
Thanks again N.P. et all.
Karl
It has had enough time to settle-in (the poly caps burned-in prior to the build) and I like it!
So much so that I had to listen to side 2 of Ziggy Stardust twice, b2b, something I never do, just because it sounded so d@#& good.
Thanks again N.P. et all.
Karl
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B1k i made for myself ended up staying in my friends system on his nc400s. So i made a new one for me, but i have an issue. Do mind it is not in a box yet (but neither is the one that friend now owns).
It hums, also it has active phone near old pc speakes ticking noise, on both channels, but only one channel plays music. Hum is persistent even without input from dac. Nutube shines the same on both sides, and voltages across the board are as follows:
T1 24.14v
T2 23.28v
T3 22.24
T4 8.94v
T5 0.627v
T6 0.657v
T7 9.52
T8 9.52
As for hum and ticking noise, i suspected interconnects but they work perfectly when i connect amp (purifi eval 1) directly to dac, dead silent(although friends interconnects were just rca, these are rca>xlr (shield to 1, signal to 2, negative to 3)). The only difference is that i made p089zb filter for this one that friend is about to get as well. I have also removed wifi router and modem from power outlet, and any other smps powered device to rule that out, and it is morning now, nothing is on atm within my apartment.
It hums, also it has active phone near old pc speakes ticking noise, on both channels, but only one channel plays music. Hum is persistent even without input from dac. Nutube shines the same on both sides, and voltages across the board are as follows:
T1 24.14v
T2 23.28v
T3 22.24
T4 8.94v
T5 0.627v
T6 0.657v
T7 9.52
T8 9.52
As for hum and ticking noise, i suspected interconnects but they work perfectly when i connect amp (purifi eval 1) directly to dac, dead silent(although friends interconnects were just rca, these are rca>xlr (shield to 1, signal to 2, negative to 3)). The only difference is that i made p089zb filter for this one that friend is about to get as well. I have also removed wifi router and modem from power outlet, and any other smps powered device to rule that out, and it is morning now, nothing is on atm within my apartment.
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Voltages all look good, so the channel with no music may be a wiring/connection issue. Double check all wiring and their solder joints to board and RCA jacks.
You mentioned rca>xlr. Simplify by using rca/rca and rca source. Try switching source from left to right and vice versa.
As for hum and noise, simplify by removing PO89ZB filter. Check that RCA jacks are not grounded to chassis.
Make sure basic preamp works properly before adding extras.
And post well illuminated and focused pictures, including overall shot of the whole preamplifier showing all wiring.
You mentioned rca>xlr. Simplify by using rca/rca and rca source. Try switching source from left to right and vice versa.
As for hum and noise, simplify by removing PO89ZB filter. Check that RCA jacks are not grounded to chassis.
Make sure basic preamp works properly before adding extras.
And post well illuminated and focused pictures, including overall shot of the whole preamplifier showing all wiring.
@Ben Mah I will resolder wiring just in case, the rca are not soldered but screwed in place connections.
I have no means to check rca to rca with amp until weekend. Source is rca so just regular cable there. It hums and ticks even eithout source connected to inputs of b1k.
I'll be removing the filter now.
Here are the pics. I have upgrade components but wanted to use kit ones first to make sure all is well before swapping caps and some resistors.
I have no means to check rca to rca with amp until weekend. Source is rca so just regular cable there. It hums and ticks even eithout source connected to inputs of b1k.
I'll be removing the filter now.
Here are the pics. I have upgrade components but wanted to use kit ones first to make sure all is well before swapping caps and some resistors.
Attachments
I've just resoldered wiring including connections on alps, removed p089zb filter. Still hum still active call noise ticking. One thing i just noticed, as right channel is working, left is not, when i turn the volume to almost zero, i can hear song coming from the left channel as well but really faintly with my ear on the speaker drivers. Also switched left to right, right output works only even switched to left.
At the cable xrl connection, there is a fourth pin (neutric xlr connector) that is ground(which connects the plug casing), and i've found conflicting info on this matter as to jump pin 1 to it, some say yes some say no, and i didn't jump it. Perhaps try jumping that point so that the ground is on the xlr side plug? But it is still a long shot from what i see because when i connect dac directly to amp via the same cable no hum, dead silence.
At the cable xrl connection, there is a fourth pin (neutric xlr connector) that is ground(which connects the plug casing), and i've found conflicting info on this matter as to jump pin 1 to it, some say yes some say no, and i didn't jump it. Perhaps try jumping that point so that the ground is on the xlr side plug? But it is still a long shot from what i see because when i connect dac directly to amp via the same cable no hum, dead silence.
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Need shots of whole preamp showing overall layout and wiring. Hum is most likely due to bad wiring, layout, execution.
It's currently on the bench table. First one was literally in plastic box and it had no hum issue. But as i said it was rca to rca, this one is rca to xlr interconnect (shield and negative soldered together at rca, at xlr end shield to 1, signal to 2, negative to 3). Don't know if that makes the difference.
Not quite. Passive hum is more like silent white noise, occasional ticks as an active phone call near old speaker. When i touch volume pot i hear different sound, bzzzzz, not the same.
Also, that passive hum is the same loudness no matter what volume i set, but that bzzz on pot touch is louder the volume is higher.
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Is this "passive hum" and "silent white noise" like a hiss? What frequency range is it?
A hum is more 60Hz and/or 120Hz and is generally associated with AC ripple and grounding issues.
Buzzing and ticking may be caused by bad connections, bad solder joints.
Have you grounded the body of the volume pot as suggested by ClaudeG? If not, then give it a try.
Looking at your board (post #7569) there are some solder joints that look a bit rough. One such joint is the V+ to the board. The line in and line out and ground wire connections to the board look rough too.
A hum is more 60Hz and/or 120Hz and is generally associated with AC ripple and grounding issues.
Buzzing and ticking may be caused by bad connections, bad solder joints.
Have you grounded the body of the volume pot as suggested by ClaudeG? If not, then give it a try.
Looking at your board (post #7569) there are some solder joints that look a bit rough. One such joint is the V+ to the board. The line in and line out and ground wire connections to the board look rough too.
I'll check the frequency tomorrow, it's almost 2am here. They look rough as i resoldered and haven't cleaned the flux, so it's a bit darkish, will brush up tomorrow. Overall soldering of components you can see on post before, with daylight clean photo. I did add 5W dale 270R meanwhile while i was at it soldering, as the 3W kit one is too hot for my taste.