A post was merged into an existing topic: Bottlehead Crack OTL AMP (Kit/DIY) - Official Thread
Just don’t eat the NOS Planters. Might give you a belly ache
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Thanks man. I actually bought the XDuuo TA-20 over a year ago but have only used it for maybe a couple hours. Didn’t hear anything really different from my SS amp. I realize it’s not even burned in yet but I also realized I didn’t want to spend money on tubes for an amp I knew I would be upgrading and might not benefit much from that $$ spent. I kinda felt the same way about spending money on the BHC since I plan on getting a DNA, A&S or other higher end amp at some point but after deliberating for probably 9 months about getting it I finally concluded ; 1. The BHC seems to be much loved even by those with much higher end tube amps. 2. I want to give DIY a shot. All the gear I bought to do this project I plan to use to make my own cables and want to give making a Raspberry Pi a shot. 3. I have the 800s and 6xx so I want to hear first hand how these HPs sound out of the Crack. Anyway, too long an explanation for a simple question… I always over explain, it’s kinda my thing😂
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Setting up a Pi involves about 4 parts and takes 5 or 10 minutes. Many audio add-on kits snap together as well. Most work/time involves custom devices and programming.
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What’s that!? Looks awesome!
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On the left is the Decware csp3 pre amp which gives you control of the left and right gain, also controls the left and right output voltage to your amp. Volume control and two quarter inch headphone Jacks to listen to at the pre amp stage. Rca and single mono out for speakers and sub or amp as i have it set up.
On the right it’s the Decware taboo mkiv with left and right volume control, high, low gain and lucid mode which allows the left channel to be heard on the right side and Vice verse plus a bypass switch if you don’t want to use lucid mode. This imitate listening to speakers with headphones, really fills the sound stage. You can control how much or how little. Two gauges showing milli amps so you know when your tubes are warmed up and when they go bad. Should be between 20 and 40 milli amps. So far, it hits right below 40. I find it pretty useful so far. I’m pretty sure this is balanced out and only comes with 4 pin xlr out but has 4 pin xlr in or rca in and speaker taps.
If you love bells, whistles and controls, these two have it. Reminds me of almost kind of steam punk.
I was thinking today about lucid mode. When you listen to your headphones, you can hear a guitar in the left ear, vocals center and drums to the right. Lucid mode fills in those empty spaces. Bringing the guitar across the stage but you still know it’s to your left but you can hear it in your right ear. And the drums can now be heard to the left but you still know it’s to the right. It goes from two dimensional to three dimensional would be one way I would try to explain it.
I’ve got quite a bit of testing, learning best practices and what sounds best to me. So I might take this post, wrap it up with some testing and what I’ve learned and repost it in the taboo model discussion.
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‘Lucid Mode’ sounds like the Crossfeed settings on Chord, iFi, and likely some other headphone amp gear as well… It can be quite effective!
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Quick blurb from the manual that explains it better than I can:
Lucid mode accomplishes two things:
-
Cross-Feed where information from the right channel is present in the left channel at
the proper level and frequencies to simulate the effect one gets from listening to
loudspeakers in a room. -
Extraction where information buried in the recordings is flushed to the surface
adding to a more live feel with more presence.
The first half of the dial is cross-feed. The second half of the dial is extraction. That is
to say that when you pass the half way point on the dial, cross-feed turns into cross-
feed AND extraction with the level of extraction increasing as you rotate the dial to full.
NOTE: Cross-feed is usually desirable on all recordings, however Extraction is more
recording dependent. For example, an audiophile recording can often sound really
good with Extraction, whereas a commercially typical recording with lots of effects
patched into the recording console will often suffer from more than a tiny amount of
Extraction. Using too much will often ruin the recording. (The prior version of the Taboo
had Cross-Feed and Extraction on two separate switches and neither were adjustable.)
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I wonder if thats just an EQ adjuster in the presence region of the FR?
That’s a Steve Decware question if I ever heard one. I couldn’t begin to answer that one. That’s above my pay grade. It would all be speculation on how it works.
I actually have some questions and scheduled some time with Steve tomorrow, I’ll have to get a 10,000 foot view how lucidity and extraction works.
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This marks the debut of my Step Stool of Unboxing in What’s in the Box!
My Crack is on my Stool [Insert joke here].
I’ll take my time digging in. The first step is to finish the wood in natural black walnut dye (i.e., simple walnuts leached in water), followed by a hand-rubbed boiled linseed oil (BLO) sealer. Sand, dry, sand, dry… After that I’ll do the metal, then ultimately get to the electrics. It won’t be finished very soon.
BLO on my Crack.
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Mmmm sexy Decwares. Only thing that has kept me from getting on the eternal waitlist for one of those is the dual volume controls. Pretty sure I would go mad trying to make sure they were perfectly balanced every time I change the volume.
Interested to hear your thoughts on how it compares to other otc amps you’ve had
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The dual volume really isn’t bad. If one side is louder than the other, you can tell it’s off balance, a little heavier than the other side. Easy to adjust. It’s actually a really nice feature, another adjustment for position or maybe your hearing isn’t as strong on both sides.
Not as powerful as some of the other amps I’ve used but a really good, clean, strong sound. It doesn’t pick up noise from phones, WiFi, etc. really quiet
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If you’re in a room with a piano the piano doesn’t play louder for your weak ear to “make things even”. Your brain sorts all this out and creates “normal” for what it has available.
I think you will find if you have a hearing imbalance and you adjust the volume on one side to “compensate” then things which should be in the middle will move toward the side you turned up.
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It absolutely does move the sounds position and visually, i can keep the volume pots what appears to be close to the same position and what sounds like to me, keeps the sound balanced.
My thoughts exactly. I adjust the volume constantly from song to song, and I just can’t see the dual pots ever working for me, and my OCD.
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I’m cautioning specifically against using channel volume as a way to compensate for hearing imbalance, as it may not work out as a “fix”.
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I’ll spare you 900 pictures of tiny parts arriving in 50 different envelopes. Ordering DIY during parts shortage is not that much fun
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It was only a thought but probably not the reason why he did it that way. Again, I have some time with him today, I’ll add that to my list of questions and curiosities.
The first day I had it, I set the volume on the Taboo to max and adjusted the volume on the CSP3 as it has a single volume, eliminating the dual volume and the question of “do I have it set correct?”. Worked with no issues and as expected.
The second day, I set the Taboo volume, left and right at 2o clock. Went back and forth between the CSP3 single volume and the Taboo. I didn’t mind the Taboo dual volume at all. But I’m going into it with an open mind and to me, even though the amps I’ve used are limited. This amp has the most versatility. No other amp I’ve used so far lets me change the left and right gain other than changing a tube. No other amp lets me change the output voltage like the CSP3 but this amp is specifically a pre amp but works wonderfully as a headphone amp alone. There are some amps out there with a high low gain switch, I have yet to find this super useful but it’s there and the ZMF headphones are not difficult to drive. No other amp I’ve used has the ability to adjust the lucidity or the ability to hear the left channel through the right and vice versa along with extraction which is a debated topic along with the ability to disable lucid and extraction. (I’ll add this to the questions for Steve) And of course, no other amp lets you control the left and right volume.
I’m going to compile all my thoughts and experiences, notes, discussions with Steve and post them in the Taboo discussion just in case someone wants a future reference. These amps seem to be pretty rare, so I figured any experience and discussion would be well taken.
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