Old image links

TypodCrow · 1193

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Offline TypodCrow

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on: February 25, 2019, 04:16:03 PM
Hey guys,

I'm trying to access an old image from the forum that was uploaded to imageshack. The post where the image is linked can be accessed here:

https://bottlehead.com/smf/index.php?topic=526.msg6045#msg6045

How might I access this image?

PS. I know I don't personally have a Bottlehead purchase, but I have a used Crack coming as a parcel as we speak. I'd like to see the curves mentioned in the above post to choose an output coupling cap for my lower impedance cans.




Offline Paul Birkeland

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Reply #1 on: February 26, 2019, 05:29:15 AM
What impedance are your low impedance cans?

The capacitor it not necessarily the limiting factor on performance.  You can put 1000uF coupling caps in and the Crack still isn't going to work well with a 32 ohm headphone.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline TypodCrow

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Reply #2 on: February 26, 2019, 08:01:16 AM
I completely understand; I plan to put output transformers on in the long run for my planars. Already sourced the parts just waiting to hit order. Need to receive the amp and make sure everything is in order first.

The output cap change is to change the corner frequency a bit for slight adjustment/just learning about how much of a difference I can hear. I understand changing the cap will also tune the sound according to the properties of the new cap. These are all topics discussed at length in other threads here.

The purpose of the OP however, was to figure out how to open those types of image links on this forum. I keep getting redirected to the imageshack login when I load the URL directly in my browser. How can I view them?



Offline Doc B.

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Reply #3 on: February 26, 2019, 09:06:32 AM
To clarify here -

We had a huge problem a while back with image links from outside sites bringing our server down. Hence we had to disallow those links. The link in the post is an old link I made to post the outside image from imagelink on our forum. Thus it has been deactivated. The original imageshack link is not mine. If you trim down what is in the post to the just the imageshack link URL and sub / for the %2 etc stuff it may get you to the original image. Or it may not, as the post is some eight and a half years old. The person who originally posted the image to imagelink would have to help you there.

If you are matching impedances with an output transformer the impedance of the cans is not what you would use to calculate the cap value anyway. You would use the reflected primary impedance of the transformer you are adding since that is the load the amp sees, and which should be in the proper range for the stock cap value, i.e. 300-600 ohms.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Paul Birkeland

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Reply #4 on: February 26, 2019, 09:48:17 AM
I completely understand; I plan to put output transformers on in the long run for my planars.
We make two headphone amplifiers that are much, much better suited for use with planar headphones.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline TypodCrow

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Reply #5 on: February 28, 2019, 08:25:04 AM
We make two headphone amplifiers that are much, much better suited for use with planar headphones.

Of course, I just recieved this kit from another builder who was having trouble debugging it. The Crack will be a boiler plate for my first forray into the world of Tubes. I'm hoping to get something like the S.E.X in the future, but this is a temporary start and a way to learn about how all of this works.



Offline TypodCrow

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Reply #6 on: February 28, 2019, 08:29:46 AM
If you trim down what is in the post to the just the imageshack link URL and sub / for the %2 etc stuff it may get you to the original image.

Gave this a shot but to no avail. No worries.

If you are matching impedances with an output transformer the impedance of the cans is not what you would use to calculate the cap value anyway.

I was hoping to set up a 3-way output switch that would let me choose between
1. Stock Capacitance
2. My modded capacitance (For something like the Etymotic ER4S which sit at 100ohm, just below the amp's output impedance)
3. Stock Capacitance into output transformers for a lower impedance can.

It seems that the transformer will render mode 2 above unnecessary. Thanks again for the input!



Offline Paul Birkeland

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Reply #7 on: February 28, 2019, 12:26:05 PM
I was hoping to set up a 3-way output switch that would let me choose between
1. Stock Capacitance
2. My modded capacitance (For something like the Etymotic ER4S which sit at 100ohm, just below the amp's output impedance)
3. Stock Capacitance into output transformers for a lower impedance can.
100uF should work just fine for 1-3.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man