Variac said:
1) Not really,
2) Yes,
3) Of course.
Andrzej Sochon said:
The die is twice as big, and you can use half as many.
😎
I didn't know either, but I have 18 of them that Nelson gave me at Burning Amp so I was quite interested. I guess one needs to pay special attention to getting the heat into the heatsink efficiently..
Hmm likely I will get enough matched out of my cache since I only need half as many!!
Always correct- sir!
But will they have the effect on a single driver that an F1 or F2 would? ie boosting the bass?
My speakers are ported and I guess that might be a problem with the F1 or F2
Hmm a big loose Aleph might be the ticket .. BECAUSE my bass driver is less efficient than my mid and tweet,
(probably due to baffle step ) so if I use an amp with gain I can adjust that and use only one preamp-genius, no? (no)
Man, my system is going to be soo unstandard 🙄 maybe screwy is a better term..
That's what is so 😎 about DIY though..
😀
Variac said:
so - in few months you and AR2 will be best friends, pouring tears together ,in some harbour pub , how your systems are complicated ....................
you don't need fluffy amp to cure what you don't have or not have ;
what you need are muscles to control that dreky cone .......... you need control of current , not looseness of it .
no matter how good F1 and F2 are , I can't see their virtues in fulfilling that task
only you can decide where you'll compensate for that difference in speakers ......... on line level or on full blast level........ whether it voltage or current full blast is ...........
tip:
you can make pretty neat voltage divider between nasty potent preamp and final amp ;
or you can simply place resistor in parallel with fostex .......... F4 will be happy
whatever
Nah! AR2 and I have already been through a lot, and I think we both want simple systems! He is reformed 
I never had the bucks for something complicated!
I want to avoid excess complexity - that's why I am thinking it through now... Or better said Complex (?) thinking now to avoid complex construction later.
"fluffy amp" Exactly describes what I was talking about!! 😉
Very good idea.. that would work with the 2 F4's then..
SO I could make a "Mini balanced F4 " as you, choky mentioned way long time ago (no need to mention it yet again!!
) for mid and tweet and use my big balanced F4's for the bass. Balanced F4 is a bit "fluffy" so would work well on bass- even if you don't approve..
eh, not so much... I've tried an Lpad and the thing gets HOT
and it isn't just a FOstex, it is a Fostex with crossover and 2si ribbon with crossover... so I really like the voltage divider idea.. thanks..
Looks like I need moamps ( not the person, more amps)
I never had the bucks for something complicated! I want to avoid excess complexity - that's why I am thinking it through now... Or better said Complex (?) thinking now to avoid complex construction later.
"fluffy amp" Exactly describes what I was talking about!! 😉
Very good idea.. that would work with the 2 F4's then..
SO I could make a "Mini balanced F4 " as you, choky mentioned way long time ago (no need to mention it yet again!!
) for mid and tweet and use my big balanced F4's for the bass. Balanced F4 is a bit "fluffy" so would work well on bass- even if you don't approve.. eh, not so much... I've tried an Lpad and the thing gets HOT
and it isn't just a FOstex, it is a Fostex with crossover and 2si ribbon with crossover... so I really like the voltage divider idea.. thanks..
Looks like I need moamps ( not the person, more amps)
Pre Amp for F4
Hello MR Variac:
Can tell me about the now famous pre amp that was built for your balanced F4 set up
Hello MR Variac:
Can tell me about the now famous pre amp that was built for your balanced F4 set up
Moin,
some people build their F4 with only one pair of IRFP240/2940.
Can the C´s on the powerboard be reduced to 1/3 or are the original values better?
What is the maximum safe voltage with 2SK170/2SJ74, I guess +-25V?
Carsten
some people build their F4 with only one pair of IRFP240/2940.
Can the C´s on the powerboard be reduced to 1/3 or are the original values better?
What is the maximum safe voltage with 2SK170/2SJ74, I guess +-25V?
Carsten
Variac said:Nah! AR2 and I have already been through a lot, and I think we both want simple systems! He is reformed
another nasty one for you :
you can drive balanced fluffy F4s for your lumpy 15" - ditto balanced from
;then - route unbalanced from
output to unbalanced stereo Mini F4 for main/high .that way maybe you'll compensate needed gain difference ;
besides - I think that you don't need dedicated amps for main and tweets ............
bwah ....... dedicated amp for eeeny weeeny tweet ?
naah , at least not bellow 2,5" ............
Carsten
Well, I don't have one yet. BUT at the show, we had both a Pumpkin without the Shunty regulator, and the mystery tube pre from SY.
I have ordered a Pumpkin with Shunty from Mr. Zenmod so he will shut up about it ! (also maybe because even without Shunty it sounded GOOOD at the show. AR2 took it home after the show (because it was his! ) and at this moment he is adding the Shunty mod. He is using it with an Aleph, so lowered the gain too. His report on extended listening: Two thumbs up! (And he only has two thumbs, unlike myself who is all thumbs...)
SY is in Europe on business so I can't try to torture the secrets out of him, but he told me that his tube pre is VERY simple and probably quite cheap, so I have to say that I am intrigued by it also. I am planning to make it too- who knows , I might WANT to have two preamps and run each amp with one..
Well, I don't have one yet. BUT at the show, we had both a Pumpkin without the Shunty regulator, and the mystery tube pre from SY.
I have ordered a Pumpkin with Shunty from Mr. Zenmod so he will shut up about it ! (also maybe because even without Shunty it sounded GOOOD at the show. AR2 took it home after the show (because it was his! ) and at this moment he is adding the Shunty mod. He is using it with an Aleph, so lowered the gain too. His report on extended listening: Two thumbs up! (And he only has two thumbs, unlike myself who is all thumbs...)
SY is in Europe on business so I can't try to torture the secrets out of him, but he told me that his tube pre is VERY simple and probably quite cheap, so I have to say that I am intrigued by it also. I am planning to make it too- who knows , I might WANT to have two preamps and run each amp with one..
Thanks Variac:
I like the idea of a tube pre amp.
I look forward to hearing more about it from SY
I like the idea of a tube pre amp.
I look forward to hearing more about it from SY
Choky,
Very good points. The problem is that my bass isn't lumpy enough 😉
The ported box is designed (by me 🙄 ) overdamped in fact
and the driver is very damped. Seems that "fluffyness" will help some. IMHO- a bit less damped would be better...
ohhh good thinkin'.. but can the ratio between balanced and unbalanced output be adjusted? I suspect I need at least 6dB more for the bass...
On the other hand, at least it will be close, then we could add the resistor/splitter or something..
I never planned on separate amp for tweet and mid, that's too much for simple old me. So we agree on that- one amp for bass, one amp for mid/high...
Carsten,
At the moment the SY pre ONLY works with a balanced amp..
Very good points. The problem is that my bass isn't lumpy enough 😉
The ported box is designed (by me 🙄 ) overdamped in fact
and the driver is very damped. Seems that "fluffyness" will help some. IMHO- a bit less damped would be better...
ohhh good thinkin'.. but can the ratio between balanced and unbalanced output be adjusted? I suspect I need at least 6dB more for the bass...
On the other hand, at least it will be close, then we could add the resistor/splitter or something..
I never planned on separate amp for tweet and mid, that's too much for simple old me. So we agree on that- one amp for bass, one amp for mid/high...
Carsten,
At the moment the SY pre ONLY works with a balanced amp..
Where was this mentioned??
Please help me on this Mr Mod. If I have a sine wave from plus to minus on the balanced output, wouldn't I simultaneously have a half (or clipped bottom) sine wave plus to ground?
In other words: I scope plus to minus and see a full sine. At the same time I scope plus to ground wouldn't I only see the top of the sine?
😕
- each leg is pulling half ; two halves make one ;
mpmarino said:I'm not bustin' on you here, my friend 😉 . I just can't understand how both outputs can be used at the same time. Please see my ugly pic.
Wouldn't this hold true??
😕
edit: I wanna 'get it'
Think single ended class A, where bias is half of output swing.
Magura 🙂
EDIT: figured my advice would be worth more, if people could actually read it
Zen Mod,
I remember you mentioning that the pre can be hooked to both balanced and un, could you give us a link to that?
As long as you aren't pulling my leg saying that it will work, it seems OK..
I remember you mentioning that the pre can be hooked to both balanced and un, could you give us a link to that?
As long as you aren't pulling my leg saying that it will work, it seems OK..
Variac said:
I can't ..... I don't remember where ......... what's difference - same drek as !@#$%^&&!!!!whatever BOSOZ ........ all combinations in-out , including minus outout leg open or closed
mpmarino said:I'm not bustin' on you here, my friend 😉 . I just can't understand how both outputs can be used at the same time. Please see my ugly pic.
Wouldn't this hold true??
😕
edit: I wanna 'get it'
lookie lookie pic ; disregard difference in frequency .......... I repeat - think Class A - both sides conducts all time ......... or - one leg is conducting all time , other side is just kibitzing and moaning ..... what's work without moaning ? .......
Attachments
Other example:
Suppose you have a YoYo in your hand, and you simultaneously walk at a steady pace in one direction.
On a time scale, the YoYo will move in a sine like curve.
Next, suppose your hand moves up and down, as you normally do to keep the YoYo in motion.
As your hand moves slower when it reaches the end of either the movement up, or down, the movement of your hand will also have a sine shape in time.
Referenced to ground, the movement of the YoYo may be a sine with the same frequency but twice the amplitude.
Hold your hand still, and referenced to the YoYo movement center axis the YoYo still moves sine like.
Suppose you have a YoYo in your hand, and you simultaneously walk at a steady pace in one direction.
On a time scale, the YoYo will move in a sine like curve.
Next, suppose your hand moves up and down, as you normally do to keep the YoYo in motion.
As your hand moves slower when it reaches the end of either the movement up, or down, the movement of your hand will also have a sine shape in time.
Referenced to ground, the movement of the YoYo may be a sine with the same frequency but twice the amplitude.
Hold your hand still, and referenced to the YoYo movement center axis the YoYo still moves sine like.
jacco vermeulen said:
Everything made sense, but the last sentence. Help.....
Love the visuals on this one, though!😀