Crack;Bottlehead OTL
Jan 28, 2021 at 8:42 PM Post #10,606 of 10,929

bagwell359

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You guys are not accounting for the force. The crack is strong with it.

Yes, it's a revaltion. It might even make some of those German cans I hate sound good.

It's even better/stronger with a E80CC as the driver.
1611884325288.png
Mine is actually an Amperex with gold pins. Have to change (or add and then a switch) resistor in the speedball board to get the most out of it, its got more output and its quiet, so quiet. It's about 1.5 inches taller than the standard tube.
 
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Jan 28, 2021 at 10:15 PM Post #10,608 of 10,929

bagwell359

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Looks like a pre1955 welded plate. Amazing tube.

I'd say so. There are two pics of my tube in the BHC thread probably in the Spring of ;20 if you are curious.
 
Jan 28, 2021 at 10:35 PM Post #10,609 of 10,929

PsilocybinCube

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Yes, it's a revaltion. It might even make some of those German cans I hate sound good.

It's even better/stronger with a E80CC as the driver. 1611884325288.png Mine is actually an Amperex with gold pins. Have to change (or add and then a switch) resistor in the speedball board to get the most out of it, its got more output and its quiet, so quiet. It's about 1.5 inches taller than the standard tube.

Tubes make the hd800 into the totl headphone.
 
Jan 31, 2021 at 1:53 PM Post #10,612 of 10,929

Bonddam

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Is anyone looking to try Bendix 6080 which I believe the Crack takes pm me if interested.
 
Feb 1, 2021 at 12:36 PM Post #10,614 of 10,929

carlman14

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Alright everyone, I have the next big modification to my franken-crack ready. Meet the tube-rectified bottlehead crack! I completely re-implemented the power supply with an oversized power transformer capable of supporting a tube rectifier. The high-voltage winding is maida-regulated for a consistent, stable, low-ripple B+ voltage no matter what rectifier is plugged in. Any 5V rectifier is supported. I've tried 5U4G, 5U4GB, 5AR4, and 596 rectifiers with great success.

One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket. This was tons of fun, and I learned a lot about power supply design in the process!

Under the hood you can see the maida regulator for the HV winding, as well as the massive heatsink attached to it. I managed to fit this while keeping all the previous upgrades in place, including the onboard DAC.

I also replaced the input wiring with shielded cable, as there were now AC lines closer to the input wiring. With the shielded wire in place, the amp is completely silent with no hum whatsoever from the new PT. It's silent using both the RCA inputs as well as using the onboard DAC.

Overall I am very pleased with how this turned out. The differences in sound are noticeable, and my BHC has never sounded this good! Aesthetically, it came out better than I expected too. I managed to fit the new transformer in such a way that it covered the massive hole in the top plate from the original transformer.

IMG_20210131_161638.jpg

IMG_20210131_163839.jpg

IMG_20210201_081612.jpg

IMG_20210201_081624.jpg
 
Feb 1, 2021 at 12:58 PM Post #10,615 of 10,929

Bonddam

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Alright everyone, I have the next big modification to my franken-crack ready. Meet the tube-rectified bottlehead crack! I completely re-implemented the power supply with an oversized power transformer capable of supporting a tube rectifier. The high-voltage winding is maida-regulated for a consistent, stable, low-ripple B+ voltage no matter what rectifier is plugged in. Any 5V rectifier is supported. I've tried 5U4G, 5U4GB, 5AR4, and 596 rectifiers with great success.

One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket. This was tons of fun, and I learned a lot about power supply design in the process!

Under the hood you can see the maida regulator for the HV winding, as well as the massive heatsink attached to it. I managed to fit this while keeping all the previous upgrades in place, including the onboard DAC.

I also replaced the input wiring with shielded cable, as there were now AC lines closer to the input wiring. With the shielded wire in place, the amp is completely silent with no hum whatsoever from the new PT. It's silent using both the RCA inputs as well as using the onboard DAC.

Overall I am very pleased with how this turned out. The differences in sound are noticeable, and my BHC has never sounded this good! Aesthetically, it came out better than I expected too. I managed to fit the new transformer in such a way that it covered the massive hole in the top plate from the original transformer.

IMG_20210131_161638.jpg
IMG_20210131_163839.jpg
IMG_20210201_081612.jpg
IMG_20210201_081624.jpg
Only a crack user would be that crazy! That’s one crazy Crack.
 
Feb 1, 2021 at 1:11 PM Post #10,616 of 10,929

HiFiHawaii808

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Alright everyone, I have the next big modification to my franken-crack ready. Meet the tube-rectified bottlehead crack! I completely re-implemented the power supply with an oversized power transformer capable of supporting a tube rectifier. The high-voltage winding is maida-regulated for a consistent, stable, low-ripple B+ voltage no matter what rectifier is plugged in. Any 5V rectifier is supported. I've tried 5U4G, 5U4GB, 5AR4, and 596 rectifiers with great success.

One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket. This was tons of fun, and I learned a lot about power supply design in the process!

Under the hood you can see the maida regulator for the HV winding, as well as the massive heatsink attached to it. I managed to fit this while keeping all the previous upgrades in place, including the onboard DAC.

I also replaced the input wiring with shielded cable, as there were now AC lines closer to the input wiring. With the shielded wire in place, the amp is completely silent with no hum whatsoever from the new PT. It's silent using both the RCA inputs as well as using the onboard DAC.

Overall I am very pleased with how this turned out. The differences in sound are noticeable, and my BHC has never sounded this good! Aesthetically, it came out better than I expected too. I managed to fit the new transformer in such a way that it covered the massive hole in the top plate from the original transformer.

IMG_20210131_161638.jpg
IMG_20210131_163839.jpg
IMG_20210201_081612.jpg
IMG_20210201_081624.jpg
What do all of those changes do to the sound? It looks like it might be capable of time travel.
 
Feb 1, 2021 at 1:40 PM Post #10,619 of 10,929

carlman14

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What do all of those changes do to the sound? It looks like it might be capable of time travel.

The regulated PSU definitely made the biggest change out of all the upgrades (aside from the speedball). Early impressions are that the sound is just flat-out cleaner and more resolving, and the bass is more defined and punchier.

Congratulations on the build the ss plug in idea is inspired

Thanks! I like having ultimate flexibility of either tube or SS rectification.
 

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