Output Capacitor Upgrading Questions
- Thread starter jrihs
- Start date
4
4krow
Guest
Eric dyes his hair
Grainger49
New member
John,
I know the old screwdriver across the cap trick, but I thought that military electronic schools taught you to use a wirewound resistor.
I know the old screwdriver across the cap trick, but I thought that military electronic schools taught you to use a wirewound resistor.
4
4krow
Guest
Actually minimal training for trainers doesn't just happen in the military. Look around you, it's the accepted level everywhere.
Grainger49
New member
I can't give an opinion for today's military, but... the training my contemporaries got was exemplary! Set this in the 1960s and 1970s. It would be a travesty if this did not endure.
monsterdonkey
New member
Capacitor DOWNGRADE question:
I'm putting together my first Crack and I've found the output caps are missing from my kit. My local electronics shop has 100uf / 160V electrolytic caps for $1.20 each. No brand name listed on the site. If I stick those in while I wait for the stock ones to arrive will my life be ruined? Any suggestions for alternatives?
Thanks
Rob
I'm putting together my first Crack and I've found the output caps are missing from my kit. My local electronics shop has 100uf / 160V electrolytic caps for $1.20 each. No brand name listed on the site. If I stick those in while I wait for the stock ones to arrive will my life be ruined? Any suggestions for alternatives?
Thanks
Rob
100uf/160V generic caps will function in the interim.
-PB
-PB
monsterdonkey
New member
I thought so. Thanks guys.
This is what happens when you are too lazy/excited to verify the BOM.
This is what happens when you are too lazy/excited to verify the BOM.
Caucasian Blackplate said:
Sorry Paul but I have another question. How long should it normally take for the power cap to go down to 0. I wanted to test it today so I powered up my Crack and measured the voltage at terminal 13. It was 172V. I next turned off the power and remeasured. It now measures 0V. Would this cap discharge so quickly? I thought it would take some time (more than 1 minute) for the cap to discharge. Does this sound right?
Thanks...Dave
The rate of discharge depends on many things.
If you have tubes that are warm and conducting, they can help draw down the voltage in the power supply.
If you have the Speedball installed, it will drain the power supply pretty quickly to around 3V.
If you have no warm tubes, no Speedball, and a loose 270K resistor, the power supply may never drain down
If you have tubes that are warm and conducting, they can help draw down the voltage in the power supply.
If you have the Speedball installed, it will drain the power supply pretty quickly to around 3V.
If you have no warm tubes, no Speedball, and a loose 270K resistor, the power supply may never drain down
Downhome Upstate
New member
Grainger49 said:
I still remember the my USAF basic electronics instructor at Keesler airplane camp explaining the difference between two components or circuit topologies (this was 1973, can't remember details). "This is the same [as the last one we discussed], only different."
JamieMcC
New member
Hi guys I have been having fun researching output capacitors for upgrading my Crack in the new year, being in the UK prices here seem to be higher than those over in the US and there is not so much choice readily available :-[ So narrowing it down the has been difficult but these two sound attractive and are within my budget.
The Obbligato 100uf 400v +-10% 45mmx90mm at
The Obbligato 100uf 400v +-10% 45mmx90mm at
JamieMcC
New member
Ok I do have some more info on the JB JFX which I decided in the end to purchase. Fingers crossed they will be a worthwhile upgrade we shall see.
Following on from my earlier post, the JFX-Premium metallized polypropylene film capacitor intrigued me and there is something about taking the path less travelled that I find attractive compared to running with the more obvious tried and tested choices for upgrading the caps in the Crack.
After some considerable time spent online getting nowhere I ended up contacting JB Capacitors direct in China.
It turns out that they have a 30 year history of capacitor manufacturing with modern machinery and production methods achieving high consistent quality to meet many international accreditations.
On to the JFX-Premium metallized polypropylene film capacitor.
These are built to high specification and JB state they regard their JFX product as being of equivalent quality as the more well know brands such as Jensen, Auricap, Erse, Mundorf, Auricap, Erse, Mallory, Jantzen Audio. Which is not a claim to make lightly I would think.
A premium grade of
Following on from my earlier post, the JFX-Premium metallized polypropylene film capacitor intrigued me and there is something about taking the path less travelled that I find attractive compared to running with the more obvious tried and tested choices for upgrading the caps in the Crack.
After some considerable time spent online getting nowhere I ended up contacting JB Capacitors direct in China.
It turns out that they have a 30 year history of capacitor manufacturing with modern machinery and production methods achieving high consistent quality to meet many international accreditations.
On to the JFX-Premium metallized polypropylene film capacitor.
These are built to high specification and JB state they regard their JFX product as being of equivalent quality as the more well know brands such as Jensen, Auricap, Erse, Mundorf, Auricap, Erse, Mallory, Jantzen Audio. Which is not a claim to make lightly I would think.
A premium grade of
JamieMcC
New member
Its been both fun and confidence building adding a couple of mods to my BHC over the last week. Earlier today it was the turn of the JB Capacitors, JFX 100uf 250v premium film caps. ;D
I still need to add some insulating tape to the cap leads and connecting wires, I will pick some up on Monday I'm a bit to worried about getting my hot air gun to close to use heat shrink sleeving.
Also on the first pic you can see how the Valab attenuator only just fits inside the case. I had glued some corner braces to the case and needed to remove one of these for the Valab to fit.
I still need to add some insulating tape to the cap leads and connecting wires, I will pick some up on Monday I'm a bit to worried about getting my hot air gun to close to use heat shrink sleeving.
Also on the first pic you can see how the Valab attenuator only just fits inside the case. I had glued some corner braces to the case and needed to remove one of these for the Valab to fit.
Is this just in my head? I need some input.
Love my crack w. speedball.
I put in 2 replacement output caps: Mundorf MKV film caps (250V 100uF) and one bypass cap: Mundorf Supreme 2.2uF during my initial crack / speedball build.
My impression when new was that with the crack+speedball+caps+ HD650s I was hearing unnoticed detail and with clearer placement of the instruments, almost like focusing an image after it's initially hazy, to compare it by visual analogy. Additionally, I could hear various aspects of the music much better, percussion in particular, subtle breaths of singers, low level distortion, reverb and other more subtle voicing effects on instruments, and woodwind instruments had an airy quality that was missing before.
All in all, pretty awesome.
I am now about 70 hours into breaking in my kit. 75% of those are running it at reasonable volume for 8 hrs or so, the rest from actual listening. I am doing this because it is my understanding that caps take about 200hrs to break in. I know this is debatable, but I figured it couldn't hurt on the off chance.
What I think I am experiencing now is that the sound seems less detailed than it initially did. Like there's a thin film over the music. It's less crisp, like the edges are rounded off the sound or something. (Sorry really failing with descriptors here)
Is this in my head because I am now used to the detail inherent in my setup, or is it possible that my caps are evolving into a less detailed sound?
Thanks in advance,
Ryan
Love my crack w. speedball.
I put in 2 replacement output caps: Mundorf MKV film caps (250V 100uF) and one bypass cap: Mundorf Supreme 2.2uF during my initial crack / speedball build.
My impression when new was that with the crack+speedball+caps+ HD650s I was hearing unnoticed detail and with clearer placement of the instruments, almost like focusing an image after it's initially hazy, to compare it by visual analogy. Additionally, I could hear various aspects of the music much better, percussion in particular, subtle breaths of singers, low level distortion, reverb and other more subtle voicing effects on instruments, and woodwind instruments had an airy quality that was missing before.
All in all, pretty awesome.
I am now about 70 hours into breaking in my kit. 75% of those are running it at reasonable volume for 8 hrs or so, the rest from actual listening. I am doing this because it is my understanding that caps take about 200hrs to break in. I know this is debatable, but I figured it couldn't hurt on the off chance.
What I think I am experiencing now is that the sound seems less detailed than it initially did. Like there's a thin film over the music. It's less crisp, like the edges are rounded off the sound or something. (Sorry really failing with descriptors here)
Is this in my head because I am now used to the detail inherent in my setup, or is it possible that my caps are evolving into a less detailed sound?
Thanks in advance,
Ryan
Paul Joppa
Moderator
In my limited experience, caps do often go through a phase where they sound worse than they did at first, before they fully are broken in. I've never seen it take that long; usually it's more like at the 20-hour point. But since the mechanism is mysterious, I can't discount this possibility.
As the alternate theory, the initial unpleasantness often includes an "edge" to the sound which can be mistaken for greater detail. When they break in fully, the edge goes away leaving behind greater resolution and subtlety - a smoother sound. It's been most audible with tape sources, I believe because they deliver the highest potential resolution.
Just two theories as alternates to the (this cap just sucks" theory.
You might try taking the bypass off - sometimes they do more harm than good, and predicting when seems impossible.
As the alternate theory, the initial unpleasantness often includes an "edge" to the sound which can be mistaken for greater detail. When they break in fully, the edge goes away leaving behind greater resolution and subtlety - a smoother sound. It's been most audible with tape sources, I believe because they deliver the highest potential resolution.
Just two theories as alternates to the (this cap just sucks" theory.
You might try taking the bypass off - sometimes they do more harm than good, and predicting when seems impossible.
