Nice workstation! Very organized! I like the Toppings dac and Tube amp! Regarding the Paradigm speaker, why don’t you test it with another amplifier first to see if the problem is intrinsic to the speaker itself.
Best,
Anand.
The small pop is just the slow discharge of the output coupling cap. It's normal, and the sound of the pop has more to do with your speakers than anything else.
Absolutely.
Use a preamp. (The best solution)
You can also increase the value of R12 to lessen feedback and increase the gain.
What's the consensus of using a 10K stepped attenuator before the input? Any unforeseen detriments to THD?
Am guessing that 10K attenuator at worst will be 10K//Zin of amp that is expecting low Z from source. Also changing global feedback ratio too.
Just want to keep it as simple as possible by adding an attenuator, what do you all think?
Am guessing that 10K attenuator at worst will be 10K//Zin of amp that is expecting low Z from source. Also changing global feedback ratio too.
Just want to keep it as simple as possible by adding an attenuator, what do you all think?
I have completed my ampcamp 1.6. Still burning in the amp using test speakers and initial impression is very good.
One thing though. I get a short (1 sec or so) low frequency whistle/hum each time I switch on the amp. It disappears quickly and amp plays without problem after. Is this normal, anybody experiencing this? Thanks for the input.
I thought I should fix this before connecting my main speakers.
One thing though. I get a short (1 sec or so) low frequency whistle/hum each time I switch on the amp. It disappears quickly and amp plays without problem after. Is this normal, anybody experiencing this? Thanks for the input.
I thought I should fix this before connecting my main speakers.
Simple ACA 1.6 Measurement 'guides'
Most people complete their kits with no problems thanks to the excellent build Guides from 6L6.
The few who do have an issue have mis-identified a component or installed it the wrong way round, or have a short from a solder blob or poor installation of the Keratherm shims etc. Even dry joints from inexperience in soldering. Ehy we all had to start some where!
So to help, I wondered if a few simple measurements would be in order. I have followed the ACA thread a while and did not find a single place that gave resistance or voltage checks for working amplifiers.
That made me think, why not consolidate the figures available and list them. Better still do a 'point to the place' picture for the best test points. (Best places so as not to short the probes to anything!) Then show those points on the schematic to aid understanding or help give a builder with a faulty amp some comparisons and a reference for discussion and solution.
The Resistance one is for comparison if you have a fault or you can use it before you apply power for the first time if you want. Just to be sure every thing is as expected and no shorts on the board or to the chassis.
The Voltage checks are for comparison again in the event of a fault. Or as a quick check all is well when doing the 12 volt bias set up.
The schematic adds a little detail as to what certain values have to be, see the notes part.
Please have a look, and let me know any silly errors and make comments as you wish.
Alan
Most people complete their kits with no problems thanks to the excellent build Guides from 6L6.
The few who do have an issue have mis-identified a component or installed it the wrong way round, or have a short from a solder blob or poor installation of the Keratherm shims etc. Even dry joints from inexperience in soldering. Ehy we all had to start some where!
So to help, I wondered if a few simple measurements would be in order. I have followed the ACA thread a while and did not find a single place that gave resistance or voltage checks for working amplifiers.
That made me think, why not consolidate the figures available and list them. Better still do a 'point to the place' picture for the best test points. (Best places so as not to short the probes to anything!) Then show those points on the schematic to aid understanding or help give a builder with a faulty amp some comparisons and a reference for discussion and solution.
The Resistance one is for comparison if you have a fault or you can use it before you apply power for the first time if you want. Just to be sure every thing is as expected and no shorts on the board or to the chassis.
The Voltage checks are for comparison again in the event of a fault. Or as a quick check all is well when doing the 12 volt bias set up.
The schematic adds a little detail as to what certain values have to be, see the notes part.
Please have a look, and let me know any silly errors and make comments as you wish.
Alan
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Great info indeed Alan! That should be extremely helpful!
If I may be so bold as to propose another addition to the guides:
- Both the very-mild, one-second-long 'spring loading' sound when powering on the speakers and the mild 'thump' when powering off the speakers is normal! It is the (-- fill in the real technical reason here-- which I assume is capacitors loading / discharging).
Almost once every other page in the main ACA thread there is a question regarding these behaviors from unexpecting builders. Perhaps this could help ease their anguishes a bit?
Best regards,
Rafa.
If I may be so bold as to propose another addition to the guides:
- Both the very-mild, one-second-long 'spring loading' sound when powering on the speakers and the mild 'thump' when powering off the speakers is normal! It is the (-- fill in the real technical reason here-- which I assume is capacitors loading / discharging).
Almost once every other page in the main ACA thread there is a question regarding these behaviors from unexpecting builders. Perhaps this could help ease their anguishes a bit?
Best regards,
Rafa.
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Hello Folks .... I've had my kit for a while and I just started putting it together. I'm having a blast! Some of my soldering leaves a bit to be desired. Let's hope it all works.
I have a question.
I'm at the point of wiring up the front panel power switch and I guess I got a bit greedy making the twisted pair of red wires that are connected to the pin of the power input jack on the back panel. I don't have enough left to make the two short pieces that connect the pub's to the front switch. But ... I have enough of the heavier gauge blue and black wire used on the speaker terminals left over to make the two needed pieces.
Am I correct in thinking that the heavier gauge wire will present no problem between the switch and the pcbs? Or do I need to find some lighter gauge wire?
And finally ... do I sound like noob?
I have a question.
I'm at the point of wiring up the front panel power switch and I guess I got a bit greedy making the twisted pair of red wires that are connected to the pin of the power input jack on the back panel. I don't have enough left to make the two short pieces that connect the pub's to the front switch. But ... I have enough of the heavier gauge blue and black wire used on the speaker terminals left over to make the two needed pieces.
Am I correct in thinking that the heavier gauge wire will present no problem between the switch and the pcbs? Or do I need to find some lighter gauge wire?
And finally ... do I sound like noob?
Hello Folks .... I've had my kit for a while and I just started putting it together. I'm having a blast! Some of my soldering leaves a bit to be desired. Let's hope it all works.
I have a question.
I'm at the point of wiring up the front panel power switch and I guess I got a bit greedy making the twisted pair of red wires that are connected to the pin of the power input jack on the back panel. I don't have enough left to make the two short pieces that connect the pub's to the front switch. But ... I have enough of the heavier gauge blue and black wire used on the speaker terminals left over to make the two needed pieces.
Am I correct in thinking that the heavier gauge wire will present no problem between the switch and the pcbs? Or do I need to find some lighter gauge wire?
And finally ... do I sound like noob?
You are correct. The heavier gauge is perfect for the job.
Alan
I've used two meters. Neither is auto sensing and I have used the middle pin. I have checked this several times with each meter.
OK .... The Man with the Momentary 36v ACA reports ...... all seems to be well. Whew!
Since I was able to bias it and now play it (It sounds great. Lovely little amp!) am I in the clear? Or should I lay awake at night wondering if I have done something that will severely shorten the life of this wonderful little beastie of an amp?
BUT .... right now let me say thank-yous to Mr. Nelson Pass, Jason, 6L6, and everyone else that providence has brought together to create this wonderful world of online audio people who inspired me to take up this little project.
I discovered this website a few years when I was googling around researching a potential speaker building project. It was then I found myself in 6L6's F5 build thread. I thought it was pretty cool. And I had already heard of Nelson Pass. So I investigated farther and the rest is history .... AMP #1 is in the Books!
I figure the only thing better than an ACA is a second ACA ..... or an F5 ... or an Aleph J ..... or ..... DON"T LET MY WIFE SEE THIS POST!
Blessings and thanks to all!
Since I was able to bias it and now play it (It sounds great. Lovely little amp!) am I in the clear? Or should I lay awake at night wondering if I have done something that will severely shorten the life of this wonderful little beastie of an amp?
BUT .... right now let me say thank-yous to Mr. Nelson Pass, Jason, 6L6, and everyone else that providence has brought together to create this wonderful world of online audio people who inspired me to take up this little project.
I discovered this website a few years when I was googling around researching a potential speaker building project. It was then I found myself in 6L6's F5 build thread. I thought it was pretty cool. And I had already heard of Nelson Pass. So I investigated farther and the rest is history .... AMP #1 is in the Books!
I figure the only thing better than an ACA is a second ACA ..... or an F5 ... or an Aleph J ..... or ..... DON"T LET MY WIFE SEE THIS POST!
Blessings and thanks to all!