Aleph J-X Amp Project

[Luke]

Luke,

some month ago I've build a balanced F5 (Patrick's Xed version), so maybe this two posts from the F5 thread are interesting for you:
post #5659
post #6043

I also have Peter's AJ-X pcbs but unfortunately no time to build one.

Uwe

thanks Uwe, tried search but found very little about F5X, I think very few have been built from what I can tell?

 

[derwhalfisch]

I've been poking around and haven't yet found a definitive answer:

What is the X in this project? Looks like the Aleph J will take an SE or bal input signal to me, so i presume the X is a bridging/parallel mod?


edit: found an answer. Ground one input and all will be well. Put myself on the wiki, down for mono blocks

 

[Jaac]

There is an Wiki for polling the interest for the Groupbuy of ALeph J-X PCB's. Look in my signiture for the link

 

[Alettagla]

Does someone allready have this amp finished with both channels functioning.
And would it be possible to report about its sound character. As in the near future I want to built this amp. I searched this forum but couldn"t find much......
Thanks in advance

 

[Pocoyo]

Dear Peter Daniel

Hi,

Will you attach your Aleph J or JX Picture Here
Waiting to look Aleph J or JX from GBer

Rgds, jeff

 

[wolf70]

Hello to everyone is the first time I write in the forum, waiting for the PCB are ready to implement the Aleph J, I wanted to make me realize the power transformer trasformatori bartolucci, I seem to cost reasonable.
I indicate that specific? 20 +20 V 600VA?

 

[ggetzoff]

R1-R3 value....

The standard Aleph J parts list shows part number 71-CMF5521K500FKEK for R1...R3 at 21k ohm, however the description shows it at 22.1k ohm. Which is correct?

Thanks,

Greg

 

[Tea-Bag]

22.1k is the correct value, but the other is not to far off. I would use the 21k is they were on hand.

 

[ggetzoff]

Teabag,

Thanks. I assume all the values that are listed as .6W should really be .25W?

 

[400]

Hi,

concerning the IRFP240 for a Aleph J-X (X-Version):

Which fets have to be matched?

Q5 <-> Q6 and Q7 <->Q8 (matched pairs)
or
Q5,Q6,Q7,Q8 (Matched quadrupels)
or
Q5,Q6,Q7,Q8 for both Aleph J-pcbs (8 matched fets)

Regards,
Marcel

 

[ggetzoff]

Q5-Q6-Q7-Q8 should be matched to .1 Vgs or better.

 

[ggetzoff]

Just received my matched IRFP240PbFs from Tech-Diy, if anyone needs them:

Tech DIY Company Store

 

[vdi_nenna]

AJX Transformer

Regarding transformer for the AJX version.

Read that 600VA is what is recommended for AJ version.
Is a 18v+18v 600VA for one channel of AJX a good starting point or should the VA starting point be a higher value, say 800VA or 1000VA per channel?

Once I get the correct info, I'll put it in the AJX Build Wiki.

Thanks,

Vince

 

[cat6man]

Just received my matched IRFP240PbFs from Tech-Diy, if anyone needs them:

Tech DIY Company Store

hey there,

i just went to that link and
1) there are no prices showing for these devices
2) i can't even find an email or phone number or contact info on the site

what am i doing wrong?

 

[cat6man]

i've received my boards from Peter (thank you!) and am starting
to get my parts orders together.

i went to mouser and found that the BOM1.1 part numbers correspond to 1/4W resistors while the BOM description calls for 0.6W resistors.

also, it's not clear to me if we want the cmf50 or cmf55 version (fit horizontally vs. fit vertically)...........which is better matched to peter's boards?

thanks

 

[fredlock]

I wasn't actually correct, the DC offset was approx 2mV, I forgot about the offset produced by the generator.

The amp runs hot: the 8x8 heatsink with 1.75 fins was way too small for 2 x 18V transformer.

For AJ-X configuration, front end components (inside white border) should not be installed. I just removed them from test channel and I'm slowly getting ready for an X

Hi Peter,

I haven't seen any recent post from you about the result of your AJ-X version. Could you share it to us what was the result and your listening experience? A picture/photo to look at would also be nice.

 

[cat6man]

has anyone used Modu boxes to house their diy projects?

modu

 

[cat6man]

Teabag,

Thanks. I assume all the values that are listed as .6W should really be .25W?

i'm ready to hit the button and order parts from mouser but the last thing i need to know is the correct R wattage.

in the BOM, si'm guessing that the .6W really should be 1/6W, in which case the .25W resistors are fine?

 

[Bill Fuss]

Mil Spec resistors are more conservatively rated, a RN55 is rated 1/8W but is actually 1/4W size.

 

[ggetzoff]

Cat6man,

Tech-Diy is out of IRFP240s right now, however, if you see the note on his site he will have them in-stock in May. I spoke to him on the phone last week and he was in the process of ordering more.


Greg