I'm not an EE but my limited understanding is that high inrush currents can damage the transformer or a capacitor; absent catastrophic failure, repeated inrush surges may shorten lifetime of either. Just about all I know if described here: Inrush current - Wikipedia
There are those who do not use inrush protection in their amps and report they suffer no adverse effects. I'm too chicken to find out....
There are those who do not use inrush protection in their amps and report they suffer no adverse effects. I'm too chicken to find out....
Changes the transformers magnetic property which can cause energy loss. My knowledge is limited on this so someone else may have a more detailed answer. From what I am seeing, you are powering up a full size capacitor bank with a almost half sized transformer. You may want to do the soft start as audiobear suggested.
Need to get thru all the pertinent points in this thread but what has been brought up tonight has me putting soft-start on the list to get parts ordered for. I ran out of 1/4" quick connects so need to get more ordered as well. Won't be working on the amps until those come in so got time to read and understand more about in-rush current problems and solutions.
These eurostyle blocks are polyamid, good to 110deg C and have internal spring contact fingers below the screws to accommodate stranded wire 20ga min 14ga max:
https://www.mouser.com/ProductDetail/Phoenix-Contact/3240167?qs=MfVUZiz0PxYzXBGsDzNowg==
You cut as many positions as you need off the 12 position strip.
https://www.mouser.com/ProductDetail/Phoenix-Contact/3240167?qs=MfVUZiz0PxYzXBGsDzNowg==
You cut as many positions as you need off the 12 position strip.
build the ACA. listen. assess. build the F6. listen. assess.
If you want to jump down the DIY audio rabbit hole, go for it. Wilh all the support here, the hardest part is ordering everything and folks will chime in with part numbers and links and such.
I still have to get my F6 monsterblocks up and running but I've been promised they will outperform the ACAs (especially with my 88dB eff. speakers).
R3 100ohm 3W
Hi,
I tried to purchase F6 parts from Mouser using 6L6's build guide BOM (post #3) and noticed the last 4 numbers printed on the 100ohm 3W resistor (R3) differ a bit from the one I received in the F6 part kit in a previous build from diyaudiostore.
Mouser CPF3100R00FKE14 - Last 4 = 2123
DIY Audio Store - Last 4 = 2025
What's the difference (if any) and is the 2123 version okay to use?
Apologies in advance for the elementary question. This will be my 3rd attempt at assembling this board, after screwing up the first two, so I just want to triple check before I solder something incorrectly (again).
View attachment 966920
Hi,
I tried to purchase F6 parts from Mouser using 6L6's build guide BOM (post #3) and noticed the last 4 numbers printed on the 100ohm 3W resistor (R3) differ a bit from the one I received in the F6 part kit in a previous build from diyaudiostore.
Mouser CPF3100R00FKE14 - Last 4 = 2123
DIY Audio Store - Last 4 = 2025
What's the difference (if any) and is the 2123 version okay to use?
Apologies in advance for the elementary question. This will be my 3rd attempt at assembling this board, after screwing up the first two, so I just want to triple check before I solder something incorrectly (again).
View attachment 966920
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Here’s a plug for the Aleph J newbie guide (see thread of that name). It’s a step by step manual which includes a Mouser shopping cart for everything- PSU as well as amp boards. As a complete newbie I can highly recommend it. I was going to build an F6 thinking its small parts count would make it easier. But I ended up busking the AJ and I’m super happy with it.
As a follow up to my previous post, I thought it best to share the BOM and respective Mfr. #'s I ordered. Can anyone confirm the amplifier and capacitor mfr. #'s are correct?
Amplifier Part Description Mfr. #
R1 0.56ohm 3W (ERX-3SJR56A)
R2 0.47ohm 3W (ERX-3SJR47)
R3 100ohm 3W (CPF3100R00FKE14)
R4 18ohm (RN65D18R0FB14)
R5 1K (CMF551K0000FEEK)
R6 47K (CMF5547K000FHEK)
R7,8,9,10 10K (CMF5510K000FKEA)
R11,12 110ohm (CMF60110R00FKEB)
R13 10K-15K (CMF5515K000FHEB)
P1,2 5Kohm 25 turn Bourns 3296W or equivalent (3296W-1-502)
Capacitor Description Mfr. #
C1,2 1000uF 25V (493-14501-ND)
Amplifier Part Description Mfr. #
R1 0.56ohm 3W (ERX-3SJR56A)
R2 0.47ohm 3W (ERX-3SJR47)
R3 100ohm 3W (CPF3100R00FKE14)
R4 18ohm (RN65D18R0FB14)
R5 1K (CMF551K0000FEEK)
R6 47K (CMF5547K000FHEK)
R7,8,9,10 10K (CMF5510K000FKEA)
R11,12 110ohm (CMF60110R00FKEB)
R13 10K-15K (CMF5515K000FHEB)
P1,2 5Kohm 25 turn Bourns 3296W or equivalent (3296W-1-502)
Capacitor Description Mfr. #
C1,2 1000uF 25V (493-14501-ND)
edwinjones4,
Your attachment shows up as an invalid link. You might want to try attaching it again.
The last 4 digits is a date code, so nothing to worry about there.
What value zeners are you using for Z1 and Z2? Also there is a recommendation
to decrease R7 and R8 to ensure adequate current through the zeners.
Your attachment shows up as an invalid link. You might want to try attaching it again.
The last 4 digits is a date code, so nothing to worry about there.
What value zeners are you using for Z1 and Z2? Also there is a recommendation
to decrease R7 and R8 to ensure adequate current through the zeners.
Edwin Jones the 4th,
R7 and R8 ideally should be 3K-5K (most choose 3.3K) to make biasing easier.
Z1 and Z2 can be anywhere from 5V to 9V, but most choose something like the 1N4733 which is 5.1V.
The F6 is a very fluid design, as such many of the parts can be deviated quite a bit and still have a working amplifier. The fluidity of the design also assists in encouraging considerable experimentation, like completely changing the input stage or using degeneration resistors with the output devices, etc...done properly, no F6 build should sound completely alike but all will sound quite 'good'!
Please double check and measure all your resistors with a DMM prior to soldering them. Ideally, one should measure caps, diodes, etc...as well but not all newbies have that capability. Set the pots, P1, P2 for 2.5K ohms or less (which is in the middle of its range) prior to turning the amp on. Make sure Q3 is a K170 and Q4 is a J74. Make sure they are matched pairs. Note the locations of Q3 and Q4 are different on each board.
Make sure you have tested your power supply first prior to connecting it to the main amp boards. You should get +/- 22 to +/-28V DC without question. Design spec is about +/-24V DC. After that is done, move on to connecting it to the main amp board. Use a variac or build a dim bulb tester for initial testing.
The 1st page of this thread has a lot of this advice. Read it several times and try to understand it. The F6 is less of a cookie cutter in design than the ACA is. Newbies tend to fail because they may make erroneous assumptions. There is less hand holding compared to the ACA, and the fact that you have to build your own supply and test it is also a pitfall. Realize that the F6 (and most Pass designs especially for newbies) is actually 2 project learning curves at once. The first is the F6 board itself. The second is building and testing a linear power supply which should be done first.
Ask Questions first, solder last. Be really, really, anal retentive! You need to be 100% sure the part is right prior to soldering it to the board. And practice soldering prior to soldering on any of the DIY Audio store based boards. Use flux if necessary.
DO. NOT. RUSH.
Good luck,
Anand.
R7 and R8 ideally should be 3K-5K (most choose 3.3K) to make biasing easier.
Z1 and Z2 can be anywhere from 5V to 9V, but most choose something like the 1N4733 which is 5.1V.
The F6 is a very fluid design, as such many of the parts can be deviated quite a bit and still have a working amplifier. The fluidity of the design also assists in encouraging considerable experimentation, like completely changing the input stage or using degeneration resistors with the output devices, etc...done properly, no F6 build should sound completely alike but all will sound quite 'good'!
Please double check and measure all your resistors with a DMM prior to soldering them. Ideally, one should measure caps, diodes, etc...as well but not all newbies have that capability. Set the pots, P1, P2 for 2.5K ohms or less (which is in the middle of its range) prior to turning the amp on. Make sure Q3 is a K170 and Q4 is a J74. Make sure they are matched pairs. Note the locations of Q3 and Q4 are different on each board.
Make sure you have tested your power supply first prior to connecting it to the main amp boards. You should get +/- 22 to +/-28V DC without question. Design spec is about +/-24V DC. After that is done, move on to connecting it to the main amp board. Use a variac or build a dim bulb tester for initial testing.
The 1st page of this thread has a lot of this advice. Read it several times and try to understand it. The F6 is less of a cookie cutter in design than the ACA is. Newbies tend to fail because they may make erroneous assumptions. There is less hand holding compared to the ACA, and the fact that you have to build your own supply and test it is also a pitfall. Realize that the F6 (and most Pass designs especially for newbies) is actually 2 project learning curves at once. The first is the F6 board itself. The second is building and testing a linear power supply which should be done first.
Ask Questions first, solder last. Be really, really, anal retentive! You need to be 100% sure the part is right prior to soldering it to the board. And practice soldering prior to soldering on any of the DIY Audio store based boards. Use flux if necessary.
DO. NOT. RUSH.
Good luck,
Anand.
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