aleph j vs aleph 3 vsn aleph 5

[maxst67]

hello I recently built an aleph j and it is just great especially in the medium to high but in the bass is a bit lacking, especially because my speakers have an impedance of up to 3.5 ohms.

not that it is decent but lacks that punch and the ability to control the bottom and then from there the idea of ​​building another aleph that is a bit more powerful at the bottom.

What is the difference between aleph j, aleph aleph 3 and 5?

Please those who have information about it to tell me any possible difference:
sound, technique, incidence of damping factor etc.

Thanks to all those who can help me

 

[Zen Mod]

J better then 3 (same power) , 5 having more muscle, even if rougher

check Aleph CCS AC gain , maybe with some tweaking for 50% you'll get what you need

 

[maxst67]

thanks ZenMod what you mean by check Aleph CCS AC gain , maybe with some tweaking for 50% you'll get what you need
and how are you going to act? increasing the bias?

 

[maxst67]

looking at the features I noticed these differences

aleph j
25 w 8 ohm
damping f 20


aleph 3 30 W into 8 ohms
60w 4, and 2 ohms
damping f 100


aleph 5
60 W into 8 ohms
90 4 ohms
damping f, 50

I conclude that aleph 3 even though it has the same power of j should drive better my speakers, right?
Only problem is only rca connection while I prefer the balanced

aleph 5 is balanced, has good power but is less refined right?

 

[Zen Mod]

search for setting Aleph AC gain

 

[koja]

Aleph30 can handle balanced inputs (this is the old aleph3 slightly improved). it can also drive impedances under 8ohm better than AlephJ (but mind you it will run HOT) and it also has more gain. I have one running on 25.5V rails (w/xformer 20-0-20). I am not sure how much difference in sound one could pick up between the two (never heard the J). Apparently AlephJ with jfet input pair measures lower in distortion and has a higher input impedance. For the gain difference if I change my 30 to J some day I am likely to add a preamp (like AlephP) in front of it.

from your comments it sounds like you may want to consider either bi-amping (p.s. I will also be adding subs to my 30 next winter), or going with a stronger amp (maybe an F5T, F5X, alephX, etc.).

good luck.

 

[Mr. dB]

from your comments it sounds like you may want to consider either bi-amping (p.s. I will also be adding subs to my 30 next winter), or going with a stronger amp (maybe an F5T, F5X, alephX, etc.).

Maybe he could convert his J to a mono JX, and then build another one just like it?

 

[maxst67]

search for setting Aleph AC gain

excuse ZenMod your answer to my question or statement which refers to?

Can you explain what you mean by search for setting Aleph AC gain😕

I'm sorry but I can not always understand certain abbreviated terms

thanks

 

[Zen Mod]

Proper Current Source Adjustment - diyAudio

meaning - ratio of current contribution of upper part of output stage in Aleph amp ;

when AC gain is lower , amp is working more as SE , when it's higher , it's more working as PP amp ..... having lower output impedance , different THD spectra

Aleph 3 is having lower output impedance (so lower DF) due to greater OLG , resulting in more NFB .......

post exact schm of circuit you're using and I'll tell you what to measure

 

[maxst67]

Proper Current Source Adjustment - diyAudio

meaning - ratio of current contribution of upper part of output stage in Aleph amp ;

when AC gain is lower , amp is working more as SE , when it's higher , it's more working as PP amp ..... having lower output impedance , different THD spectra

Aleph 3 is having lower output impedance (so lower DF) due to greater OLG , resulting in more NFB .......

post exact schm of circuit you're using and I'll tell you what to measure

I hope I have understood your request: I'm using the same pattern as the guide for 6L6 aleph j.
I purchased on the pcb diy audio shop
thanks

 

[Zen Mod]

so you're pretty much capable of putting link or exact schematic here

 

[Zen Mod]

some more readings :

You may try this: spreading bias over more MOSFETS in aleph 5 - diyAudio

You guys get always excited when talking about active current source:
R21? and Current Source AC Current Gain - diyAudio

Aleph5....it works!!! - diyAudio

 

[maxst67]

thanks again

the link that I followed the schema for aleph j is:

http://www.diyaudio.com/forums/pass-labs/241729-aleph-j-illustrated-build-guide.html

 

[Zen Mod]

ref. to this schmtc

connect dummy load to amp's out

feed it with , say, 1KHz sine ( PC , CD as source , whatever you have ) ...... few volts of amplitude at amp's output is fine

measure AC voltage across R21,R22,R23,R24 group ; call it a group
calc current as Ia=Ua/Ra , where Ra is 0R47/4

that's , incidentally , output current

measure AC voltage across R16 (or R17) ; call it ( both of them together) b group

calc current of b group as Ib=2 x ( Ur16/R16)

when Ib is 50% of Ia , Aleph CCS AC gain is 50%

you can try AC gain anything between 30% and 50% and leave where you like it most

alter AC gain varying value of R24 ; put trimpot there for testing purposes , then replace it with adequate fixed resistor

then , if you can't find definitive solution ...... you just need bigger output stage (more output pairs , bringing more OLG , thus lower DF ) .......... or bigger amp

 

[maxst67]

thanks a lot ZenMod all clear, only 2 questions

when you say to measure the CA tautness of resistance is on the group r20, r21, r22, r23 as you wroteor r21 , r22, r23, r24?

I did not understand how to generate a 1kHz signal from the PC or CD

I apologize for my incompetence
thanks

 

[Zen Mod]

download this : NaTCH Engineering - SigJenny an Audio Signal Generator for Free

install it

connect audio cable from your PC analog audio out to amp input ( one at a time )

rest is already explained

or you can use test CD with 1KHz sine track ; play it in your CD player , connected in usual manner to power amp (preamp , or just attenuator )


regarding

.....
measure AC voltage across R21,R22,R23,R24 group ; call it a group...........

sorry - that was a typo

it needs to be

measure AC voltage across R20,R21,R22,R23 group ; call it a group

 

[maxst67]

thank you very much

 

[maxst67]

download this : NaTCH Engineering - SigJenny an Audio Signal Generator for Free

install it

connect audio cable from your PC analog audio out to amp input ( one at a time )

rest is already explained

or you can use test CD with 1KHz sine track ; play it in your CD player , connected in usual manner to power amp (preamp , or just attenuator )


regarding




sorry - that was a typo

it needs to be

measure AC voltage across R20,R21,R22,R23 group ; call it a group

thank you very much

 

[maxst67]

ref. to this schmtc

connect dummy load to amp's out

Sorry ZenMod you mean by dummy load, a resistance, for example, 8 ohm 10 w?

or I can leave the same load as the speaker?

then I have another question addressed to all as well as ZM:

when building a power supply for a class A amplifier up to what is permissible oversize transformer capacity and to have a better sound?

in other words there is a size limit above which you do not have the most benefits for the quality of sound?

thanks

 

[Zen Mod]

sky is the limit ........

use this for thinking ...... http://tinyurl.com/yc3fqhg


read help , to learn how to use it best

read this http://www.firstwatt.com/pdf/art_power_supplies.pdf and think about myriad of examples of other's builds


edit : dummy load is usually same as declared nominal load , power - enough to not burn it while testing