Crack;Bottlehead OTL
May 10, 2021 at 1:04 PM Post #10,936 of 12,304
Looks nice! Do you like the sound with Speedball more, or without?

I'm running JAN 6AS7G as well. Really smooth tube. I'm looking at input tubes to replace my RCA cleartop, to me its a bit too forward and can end up sounding too shouty in mid-forward headphones. Do you like the Phillips ECC82?
To be honest, I think it's too early to tell which sound I like. Haven't even rolled in my better tubes yet. But I will say the noise floor is dramatically different. I also figure that some of the difference I'm hearing right now in terms of less background stuff is from the pot change. Getting overzealous and doing both Speedball and pot swap at the same time might have hampered my ability to test the outcomes.

The Philips is fine, but I prefer my RCA cleartop. I got a pair of the Philips to try and plop into a Liquid Platinum, and they ended up being replaced rather quickly by RCA cleartops. Generally I like using 6SN7 variants with a Garage1217 adapter - either my Sylvania metal-base or my brown-base CBS/Hytron. Then again, I built the Crack after a whole lot of tube-rolling on a Darkvoice, so maybe it's just what I have on hand...

(Also a HUGE fan of putting a dual-6J5 adapter into a 6SN7 socket... haven't tried yet on the Crack running 12AU7-6SN7 adapter then 6SN7-dual 6J5 adapter. But I will.)
 
May 10, 2021 at 1:34 PM Post #10,937 of 12,304
Speaking of double-adaptering... this sounds amazing:

IMG_1282.jpg


Still the RCA 6AS7 in the back, 12AU7 socket is being converted to a 6SN7 which is in turn being converted into two 6J5s. I have two Super Silvertone 6L5 tubes in there. This is possibly my favorite driver tube setup from my Darkvoice, and it sounds fabulous here, too. Hoping @Deyan can make me a 12AU7 --> dual 6J5 adapter to skip the adapters-on-adapters thingy.
 

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May 10, 2021 at 1:38 PM Post #10,938 of 12,304
Sorry for blathering so much, but wow... "Hey Jude" has this left-channel acoustic guitar part that is just buried in the background, but with my Crack set up like you see above and my Auteurs, it's so clear and just... hearable. I love hearing parts of songs I've listened to forever but never noticed.
 
May 10, 2021 at 1:45 PM Post #10,939 of 12,304
Upgraded my Crack - after having it built for a couple of months, I finally added the Speedball package and replaced the stock pot with a 20k DACT-style stepped attenuator.

Other than being an idiot and miswiring the attenuator the first time, it sounds really great! I re-did the braided wire from the inputs to the pot, too. All in all, a DEAD SILENT noise floor, whereas the old pot/lack of Speedball had some static popping up enough to be annoying in the right channel.

Now I just need a better knob, because this one I got from eBay is just absurd looking.



Philips ECC82/12AU7 in the front with a RCA 6AS7 in the back. Not my everyday tubes, but a couple that are nice but I won't be too sad if I f'ed up something in the wiring and they melted. But they didn't. So huzzah.
Great job Dewey! I agree the knob is a bit out of place ,lol. I need to do my speed ball but I'm in no rush. I want to burn this in for a month or so then go ahead and install.
It's funny that you need to rip out parts that you installed like the large resistors but all in the name of progress I guess..
Can you PM me where you got the attentuator?
 
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May 10, 2021 at 1:47 PM Post #10,940 of 12,304
Looks nice! Do you like the sound with Speedball more, or without?

I'm running JAN 6AS7G as well. Really smooth tube. I'm looking at input tubes to replace my RCA cleartop, to me its a bit too forward and can end up sounding too shouty in mid-forward headphones. Do you like the Phillips ECC82?
Try a Tung Sol 5998 or a GE 5998A
 
May 10, 2021 at 1:49 PM Post #10,941 of 12,304
Sorry for blathering so much, but wow... "Hey Jude" has this left-channel acoustic guitar part that is just buried in the background, but with my Crack set up like you see above and my Auteurs, it's so clear and just... hearable. I love hearing parts of songs I've listened to forever but never noticed.
I had the same epiphany when listening to the Beatles' song Come Together. You can actually hear John Lennon whisper "shoot me" in the beginning of the song....gives you goose bumps. I never noticed that until I had a good set of headphones/amp.
 
May 10, 2021 at 1:57 PM Post #10,942 of 12,304
I had the same epiphany when listening to the Beatles' song Come Together. You can actually hear John Lennon whisper "shoot me" in the beginning of the song....gives you goose bumps. I never noticed that until I had a good set of headphones/amp.
Beatles are good for that. First time I listened to my Auteurs it was the "ooh la la la"s in You Won't See Me.
 
May 10, 2021 at 2:43 PM Post #10,943 of 12,304
If anyone wants to try a different Bottlehead amp I’ve posted my upgraded mainline in the classifieds. Will I regret it? Yea probably :).

Interested in trading for a Bottlehead sex or their new estat amp. Love me some Bottlehead!
 
May 10, 2021 at 2:52 PM Post #10,944 of 12,304
To be honest, I think it's too early to tell which sound I like. Haven't even rolled in my better tubes yet. But I will say the noise floor is dramatically different. I also figure that some of the difference I'm hearing right now in terms of less background stuff is from the pot change. Getting overzealous and doing both Speedball and pot swap at the same time might have hampered my ability to test the outcomes.

The Philips is fine, but I prefer my RCA cleartop. I got a pair of the Philips to try and plop into a Liquid Platinum, and they ended up being replaced rather quickly by RCA cleartops. Generally I like using 6SN7 variants with a Garage1217 adapter - either my Sylvania metal-base or my brown-base CBS/Hytron. Then again, I built the Crack after a whole lot of tube-rolling on a Darkvoice, so maybe it's just what I have on hand...

(Also a HUGE fan of putting a dual-6J5 adapter into a 6SN7 socket... haven't tried yet on the Crack running 12AU7-6SN7 adapter then 6SN7-dual 6J5 adapter. But I will.)
How does the DV compares to the Crack with and without Speedball ?
 
May 10, 2021 at 3:33 PM Post #10,945 of 12,304
How does the DV compares to the Crack with and without Speedball ?
It holds its own nicely. Now, to be fair I've done a LOT of upgrading to the DV... all the 6SN7 socket resistors were replaced, both tube sockets were replaced, the pot was upgraded first to an Alps 50k with a shunt mod, then to a stepped attenuator, I installed, removed and reinstalled a Fitz mod, the heater cables were replaced with a twisted pair, the power switch was replaced, and a virtual center tap was created. Here's the guts of the DV more or less right now (still has the Alps in it, but you get the idea):

IMG_0855.jpg


So it's not so much a direct DV-vs-Crack comparison. That said, I'd probably say that the modded DV is pretty much on par with a baseline Crack, whereas the Speedball (so far) sounds much better than either/both.

Now that the Speedball is in and the DV has been relegated to "other OTL amp" status, I'm planning on experimenting further yet. I've got some Nichicon caps to replace those six red ones. I'll never be as aggressively talented at this as the folks I learned from in the DV tuberolling thread, but hey, it's fun!

TL:DR response to your actual question:

Crack + Speedball >>> Crack == Modded DV >>>>>>>> stock DV.
 
May 10, 2021 at 3:48 PM Post #10,946 of 12,304
It holds its own nicely. Now, to be fair I've done a LOT of upgrading to the DV... all the 6SN7 socket resistors were replaced, both tube sockets were replaced, the pot was upgraded first to an Alps 50k with a shunt mod, then to a stepped attenuator, I installed, removed and reinstalled a Fitz mod, the heater cables were replaced with a twisted pair, the power switch was replaced, and a virtual center tap was created. Here's the guts of the DV more or less right now (still has the Alps in it, but you get the idea):

IMG_0855.jpg

So it's not so much a direct DV-vs-Crack comparison. That said, I'd probably say that the modded DV is pretty much on par with a baseline Crack, whereas the Speedball (so far) sounds much better than either/both.

Now that the Speedball is in and the DV has been relegated to "other OTL amp" status, I'm planning on experimenting further yet. I've got some Nichicon caps to replace those six red ones. I'll never be as aggressively talented at this as the folks I learned from in the DV tuberolling thread, but hey, it's fun!

TL:DR response to your actual question:

Crack + Speedball >>> Crack == Modded DV >>>>>>>> stock DV.
Well clear enough 🙂
What cans were you using ?
 
May 10, 2021 at 3:49 PM Post #10,947 of 12,304
Well clear enough 🙂
What cans were you using ?
ZMF Auteurs mostly. Some ZMF Verite Closeds, but those typically live in my bedroom with my Liquid Platinum (also recently up off the upgrade bench).
 
May 10, 2021 at 3:53 PM Post #10,948 of 12,304
ZMF Auteurs mostly. Some ZMF Verite Closeds, but those typically live in my bedroom with my Liquid Platinum (also recently up off the upgrade bench).
a 300 Ohms cans would definitely weigh in especially with the Crack, I have a Focal rated at 80 Ohms, not that great mating with the BHC
 
May 10, 2021 at 3:57 PM Post #10,949 of 12,304
a 300 Ohms cans would definitely weigh in especially with the Crack, I have a Focal rated at 80 Ohms, not that great mating with the BHC
Yeah, the ZMFs love OTL amps. So do my old AKG K240s (600 ohms). How do the Focals sound w/the BHC?
 
May 10, 2021 at 4:05 PM Post #10,950 of 12,304
Last week i started helping my friend building the crack for the first time. We got an older unbuilt kit off ebay recently. It was quite an experience. So far it sounds good. Next will be wiring in the mods and speedball. I made a small case for the Cree Diodes and test mount the Choke. Everything seems to fit perfectly.

Base_BHCrack.jpeg

Cree_Diodes.jpeg

Cree_Choke_Back.jpeg

Cree_Choke_Top.jpeg

Cree_Choke.jpeg
 

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