I got my Korg Pre amp working...For years I have had the BOSOZ pre amp.
The system is a passive line level crossover using four channels of BOSOZ then L/C filter, then to Aleph J amps. This is an awfully good combination...
So now, four channels of Korg Pre amp to L/C filter. I discovered that the filter in this combination is more sensitive to terminal impedence... can't go directly to Aleph J's without throwing off the filter slopes. So now Korg Pre amp to L/C filter to terminating resistor to B1 buffer to Aleph J amps. In this combination, I worked on the filter slopes to get them closer to ideal.
The korg pre amp certainly sweetens things up. I think there is more bass. The presentation is different from the BOSOZ pre amp. I am a little deaf...but I think I hear some of that 1% to 2% distortion. I used Panasonic PP in the KORG .
So right now, I can't say which I like better, the BOSOZ or the Korg...both are great but different...
The system is a passive line level crossover using four channels of BOSOZ then L/C filter, then to Aleph J amps. This is an awfully good combination...
So now, four channels of Korg Pre amp to L/C filter. I discovered that the filter in this combination is more sensitive to terminal impedence... can't go directly to Aleph J's without throwing off the filter slopes. So now Korg Pre amp to L/C filter to terminating resistor to B1 buffer to Aleph J amps. In this combination, I worked on the filter slopes to get them closer to ideal.
The korg pre amp certainly sweetens things up. I think there is more bass. The presentation is different from the BOSOZ pre amp. I am a little deaf...but I think I hear some of that 1% to 2% distortion. I used Panasonic PP in the KORG .
So right now, I can't say which I like better, the BOSOZ or the Korg...both are great but different...
Hello to the forum! In the Moment I’m trying to build this nice little machine. Today I finished the Power section of the board. My problem is that I now tried two NEW wall wart power supplies, but they deliver 24,9 and 25,1 Volts so I get 9,8 and 10 Volts at T4. Is this a problem? Should I search for a better one?
Best regards and thank you all,
Sebastian
Best regards and thank you all,
Sebastian
Dear Mr Pass, thank you very much for your answer. I’m Shure I used the correct Values, a Vishay CMF55 270Ohms 3W and a Zener Diodes 9.1V 1W Zener Diode.
I will now build the rest of the board and test again. Maybe the values will change a bit when the power source gets a real load. If it does not work I will get back to the forum for sure. If it works too
I will now build the rest of the board and test again. Maybe the values will change a bit when the power source gets a real load. If it does not work I will get back to the forum for sure. If it works too
Now I really need your help. I now completed the board but I can’t get it to work properly. The Triode does not glow. My measurements are:
T1: 25,5
T3: 18
T4: 8,7
T5: 0,6
T6: 0,6
T7: 1
T8: 1
I have no clue what is wrong. The only thing that bothers me is, that the two 100Ohm resistors get really hot:
What’s wrong? Could anybody help!
Best regards, Seb
T1: 25,5
T3: 18
T4: 8,7
T5: 0,6
T6: 0,6
T7: 1
T8: 1
I have no clue what is wrong. The only thing that bothers me is, that the two 100Ohm resistors get really hot:
What’s wrong? Could anybody help!
Best regards, Seb
Attachments
Now I really need your help. I now completed the board but I can’t get it to work properly. The Triode does not glow. My measurements are:
T1: 25,5
T3: 18
T4: 8,7
T5: 0,6
T6: 0,6
T7: 1
T8: 1
I have no clue what is wrong. The only thing that bothers me is, that the two 100Ohm resistors get really hot:
What’s wrong? Could anybody help!
Best regards, Seb
T1: 25,5
T3: 18
T4: 8,7
T5: 0,6
T6: 0,6
T7: 1
T8: 1
I have no clue what is wrong. The only thing that bothers me is, that the two 100Ohm resistors get really hot:
What’s wrong? Could anybody help!
Best regards, Seb
Attachments
@ Seb
Your jfets are in reverse direction and probably 332K resistor mesure only 3300 Ohms ?
B1 with Korg Triode
All 10uF capacitors are on the board , inputs etc.?
Your jfets are in reverse direction and probably 332K resistor mesure only 3300 Ohms ?
B1 with Korg Triode
All 10uF capacitors are on the board , inputs etc.?
@ Seb
check with Ohmeter if all resistors values are correct ?
6L6 build guide are helpful Korg NuTube B1 guide
Best regards
check with Ohmeter if all resistors values are correct ?
6L6 build guide are helpful Korg NuTube B1 guide
Best regards
Thank you for your interesting suggestion. Bad to here that about the muse kz. I read in another place, that they are good. But in the signal path I’m only using Clarity Caps polypropylene capacitors. Do you think I will be fine with it? I picked the values 0,47uf, 1uf and 10uf. Do you think I should change the other muse capacitors too?
The korg, like other tubes are already rather bright... Silmic as per bom already works pretty good..believe me it's more than enough high.. If want to go fancy try black gates N 47uf.
Tubes you want warmth and big.. Isn't it.. The more boutique the supply caps usually sound cleaner and at expense off less . texture or warmth, however wider and more dymanic sound though.. Usually.. So just use as per bom.. Or try nhg Panasonic..kmq range nippon. It's less bright and warm sounding and good body and bass.
All types Muse is very coloured. Unless you know the sound very well and know when to use them.. Or you can just try to see if right... Can always change later. I learn it the hard way and learn to respect the designer as the part choice and topology . Not that you can't tweak them.. It takes Alot of money, time and passion.. Also a pair of good ears. Those forum reviewers... I read all and sorry.. It gave me idea.. Tried all not as simple as that..
There is a YouTube video.. Mister wizard asistant and John curl... About this subject. They designed something with specified bom..some smart guy in production changed to something more expensive and Ops.. Sounds very bad .comes down just to a too good feedback R causing issues
So..I learn to respect audio designers like Papa and wizard assistant Alot..
Tubes you want warmth and big.. Isn't it.. The more boutique the supply caps usually sound cleaner and at expense off less . texture or warmth, however wider and more dymanic sound though.. Usually.. So just use as per bom.. Or try nhg Panasonic..kmq range nippon. It's less bright and warm sounding and good body and bass.
All types Muse is very coloured. Unless you know the sound very well and know when to use them.. Or you can just try to see if right... Can always change later. I learn it the hard way and learn to respect the designer as the part choice and topology . Not that you can't tweak them.. It takes Alot of money, time and passion.. Also a pair of good ears. Those forum reviewers... I read all and sorry.. It gave me idea.. Tried all not as simple as that..
There is a YouTube video.. Mister wizard asistant and John curl... About this subject. They designed something with specified bom..some smart guy in production changed to something more expensive and Ops.. Sounds very bad .comes down just to a too good feedback R causing issues
So..I learn to respect audio designers like Papa and wizard assistant Alot..
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Cornell dubilier 940c here... affordable PPP caps and not bright sounding.
10uF for the last cap... unless you have these already handy and don't need to buy them, your power amp must have an awfull input impedance in the 3kR region.
As of me I would steer clear from any power amp with less than 10k input impedance, and for that "worst case" 3uF for the last cap are fine.
Just IMHO, in hope to help saving some $ and headache
Claude
10uF for the last cap... unless you have these already handy and don't need to buy them, your power amp must have an awfull input impedance in the 3kR region.
As of me I would steer clear from any power amp with less than 10k input impedance, and for that "worst case" 3uF for the last cap are fine.
Just IMHO, in hope to help saving some $ and headache
Claude
Claude, do you think 0,47 is OK input instead of your suggested 0,22?
And maybe 2.7 output?
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Allow me to requote papa who said it again and again .
Alot of people are missing the boat on Elna silmic.
I had been in this shoe, I made few preamp clones for friends to practice, with permission from Tron . Use just parts that close to original . Some smart fella reviewed it and ' upgraded' it ..guess what ..since I made a few (me a busy body)and it was compared .that friend 1 yr later contacted me and whine and whine sound bad ..I
I had to redo his project .. Mr Tricker is great designer for tubes ...he made his choice on parts for good reasons . What's so hard to respect that and copy.. I was as frustrated .. FYI , the original one is still the best ..... I spent 4 years copying and still not perfect . Still a fool. Only a little smarter after all this ..and humbled
Alot of people are missing the boat on Elna silmic.
I had been in this shoe, I made few preamp clones for friends to practice, with permission from Tron . Use just parts that close to original . Some smart fella reviewed it and ' upgraded' it ..guess what ..since I made a few (me a busy body)and it was compared .that friend 1 yr later contacted me and whine and whine sound bad ..I
I had to redo his project .. Mr Tricker is great designer for tubes ...he made his choice on parts for good reasons . What's so hard to respect that and copy.. I was as frustrated .. FYI , the original one is still the best ..... I spent 4 years copying and still not perfect . Still a fool. Only a little smarter after all this ..and humbled
Hi Kosscher,
of course 0,47 is also OK, what you want is not going LOWER than 0,22.
Enjoy
Hi Anthony,
I am with you generaly speaking, it is indeed a matter of cooking receipt and consistency, but browse here on a comment from Papa following my cap tweak...it "could" be that the recent Elna Silmics aren't anymore what they used to be. I can't comment on that as I purchased only new (recent) ones, all I can say is that to my ears (and to some other ears now), having taken the pain to fit Silmics first and then replace them with 940C (not all in one go to appreciate differences) just for the sake of comparison (me wanting the best to my ears) and to share experience reporting to others here (avoiding potential waste of time and money), IMHO the 940C sounded better in all aeras (see my post) while not having any drawbacks at all vs the Silmics I had purchased new from Mouser's.
Having non forgiving magnetostatic LS, I too do not like bright sounding components and being lazy I decided since to stick to 940C
However, "sound and colours", people might of course feel differently, each his own, and there is of course nothing wrong with Simics and values... Caps debate is not something clear cut and can easily pollute a thread. All I wanted is reporting on what I felt was a worthy addition to an already excellent preamp.
Have fun all of you, as that is what matters!
Claude
of course 0,47 is also OK, what you want is not going LOWER than 0,22.
Enjoy
Hi Anthony,
I am with you generaly speaking, it is indeed a matter of cooking receipt and consistency, but browse here on a comment from Papa following my cap tweak...it "could" be that the recent Elna Silmics aren't anymore what they used to be. I can't comment on that as I purchased only new (recent) ones, all I can say is that to my ears (and to some other ears now), having taken the pain to fit Silmics first and then replace them with 940C (not all in one go to appreciate differences) just for the sake of comparison (me wanting the best to my ears) and to share experience reporting to others here (avoiding potential waste of time and money), IMHO the 940C sounded better in all aeras (see my post) while not having any drawbacks at all vs the Silmics I had purchased new from Mouser's.
Having non forgiving magnetostatic LS, I too do not like bright sounding components and being lazy I decided since to stick to 940C
However, "sound and colours", people might of course feel differently, each his own, and there is of course nothing wrong with Simics and values... Caps debate is not something clear cut and can easily pollute a thread. All I wanted is reporting on what I felt was a worthy addition to an already excellent preamp.
Have fun all of you, as that is what matters!
Claude
ClaudeG
My revisiting your description of the Cornell Dubilier 940C is a timely happening.
I searched out and Bookmarked your thread on how you have perceived the performance of this Cap', and it seems this might be one that needs to be on my shortlist.
I at present am using a recently built KB1, that has been loaned to me,
it is exceptional and surpasses my other Pre' that was not so revealing of differences during my 6SN7 Tube Rolling on my Mono Block Power Amp's.
The Tube of choice is a Ken Rad VT231, but when this is paired with the loaned KB1, it pushes a little hard on my eardrum with the Upper Frequencies, and is a detractor over time.
I have expressed to the builder of the KB1, a wish to learn how to lessen this effect,
to enable the VT231 to be used as the main valve, instead of others I have been rolling,
to good effect with the KB1.
For reasons unknown to me, the Tube Rolling with the KB1, shows differences between valves not perceived in previous rolling experiences.
Your description of the 940C sounds like it might just deliver the desired effect I am in want off.
I am fortunate to have a variety of different Cap's in use on KB1 Builds within my local HiFi Group, with this in mind, I know nearer the time of my build, I will be able to try a few models with different Cap's and different usage periods behind them,
with the VT231 in use, this might show out a relationship that is my preference, if not,
I will be very much considering the 940C.
My revisiting your description of the Cornell Dubilier 940C is a timely happening.
I searched out and Bookmarked your thread on how you have perceived the performance of this Cap', and it seems this might be one that needs to be on my shortlist.
I at present am using a recently built KB1, that has been loaned to me,
it is exceptional and surpasses my other Pre' that was not so revealing of differences during my 6SN7 Tube Rolling on my Mono Block Power Amp's.
The Tube of choice is a Ken Rad VT231, but when this is paired with the loaned KB1, it pushes a little hard on my eardrum with the Upper Frequencies, and is a detractor over time.
I have expressed to the builder of the KB1, a wish to learn how to lessen this effect,
to enable the VT231 to be used as the main valve, instead of others I have been rolling,
to good effect with the KB1.
For reasons unknown to me, the Tube Rolling with the KB1, shows differences between valves not perceived in previous rolling experiences.
Your description of the 940C sounds like it might just deliver the desired effect I am in want off.
I am fortunate to have a variety of different Cap's in use on KB1 Builds within my local HiFi Group, with this in mind, I know nearer the time of my build, I will be able to try a few models with different Cap's and different usage periods behind them,
with the VT231 in use, this might show out a relationship that is my preference, if not,
I will be very much considering the 940C.