Massdrop x Alex Cavalli Tube Hybrid Amp (CTH) Discussions | Drop

Jan 30, 2021

I am getting static from mute through about 1:00 on the volume knob and then again close to full volume. Any ideas on what I should try to fix this?

Jan 30, 2021

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Feb 1, 2021

NWcherokeeok, so I am giving Fayne's post below a shot and have an inexpensive JJ tube on order. If that solves my issue, I think I will try out the Genalex and keep the JJ tube as back-up. Crossing fingers.....

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Feb 1, 2021

Sterkoff

Feb 4, 2021

NWcherokeegood luck

(Edited)

Feb 4, 2021

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Feb 5, 2021

NWcherokeeHopefully that solves it. If not, there are a variety of other things that could be the cause. It could be a grounding loop. Does the amp do the crap noise only when plugged in via RCA to your DAC? If so, is likely ground problems. It could be interference from other devices. Try moving the amp and/or plug the brick into a different power strip or wall socket. Using something like a UPS will tend to filter out the power noise. It could also be the actual volume potentiometer. Not much to easily fix there. I've not had problems with mine, and all my fixes there would involve a soldering iron, so not likely useful. It could also be the power brick itself. Not likely, but they are standard cheapo bricks from China. I'd save replacing that for worst case, last option. Places like mouser sell bricks, and you can be sure it isn't a knock-off.

Feb 5, 2021

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Feb 5, 2021

FayneJust got the JJ tube in the mail this afternoon and the noisy 'sounds of the ocean' are gone when I turn the volume knob. Problem solved. I already have this plugged into a UPS and actually I have the CTH + SDAC but commented here because of the similar problem. Side note, this new JJ E88CC / 6922 tube does seem to sound better but I really have no way of knowing if there is any difference from stock. I could get the Genalex but not sure if it would be a worthwhile $45 investment... I had been using my SMSL SP200 THX amp wth a Topping E30 instead lately, but I forgot how much I also enjoy the more musical/fuller sound of the CTH. Makes me think about selling the SP200 and pick up a DROP 789 to create a nice stack to switch between....

Feb 5, 2021

Feb 5, 2021

NWcherokeeEach major production of tube has a different sound. I generally find the JJs to have more bass, whereas the Russian tubes (current prod Genalex, Tung-Sol, ElectroHarmonix, Sovtek, Mullard) all generally have crystal clear treble and tight mids. I like them all, but lately I've been using JJ everywhere. The Genalex are pretty great if you're on a classical kick and not wanting to blow way too much money on NOS. I cannot say enough good things about the 789. It is an amazing amp for the price. I jumped on the initial release and have not regtreted it at all. It works with every set of cans and IEM I've thrown at it, with very much power to spare. The LCX is also pretty awesome amp, but totally not the wire with volume control you get from the 789. I also jumped on that one when it first dropped, kinda regretted it initially because the 789 came out shortly afterwards but lately have been using it a lot. I find that the LCX is more colored towards bass and mids, working pretty excellently with all cans and IEMs I've tried with it, especially so with Planar. Anyways, I'm glad that swapping the tube was the solution.

Feb 5, 2021

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Feb 8, 2021

FayneThanks again. The more I listen to it, the more I like this JJ tube. Side note though.. I have the version with the built-in Grace SDAC and I decided to run this with my Khadas tone board through the RCA instead and compared the 2 back and forth. No question that the Khadas offer a tad more detail or brightness. For instance, upper bass is just more concise, but lower bass remains the same. I prefer this sound for sure. I wonder if this is the difference between the DAC chips, implementation or just the difference in using the RCA imputs?

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Feb 8, 2021

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Feb 8, 2021

NWcherokeeYeah, I've the CTH+SDAC also. I haven't used the integrated SDAC much past my initial testing to make sure it works, which it does. I wasn't overly impressed with the DAC itself, but I'm generally not a huge fan of AKM. I mean, I use the SDAC balanced for feeding Roon into my mixer, but I mostly use a SMSL M500 and Airist R-2R (with all of its issues) for any real listening. The Khadas uses ESS and I bet you're hearing the difference between the inherent tuning or sound signatures of the DACs themselves.

Feb 8, 2021

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Feb 27, 2021

FayneUpdate: I picked-up and have been listening to an open-box Cavalli LCX that I couldn't pass up since it cost the same as my E30 DAC. So far, it really is similar to the CTH but more resolving. Compared to the SP200 it really has a nice lower end warmth. Point is, I am even more happy that I took your advice on the JJ tube since I have been reading (and listening to it) that it is a little darker than some of the other highly rated tubes. I would imagine that getting the Genalex would only move the sound signature of the CTH closer to the LCX which would be pointless for me personally. If anything, I would want to go the other way to differentiate them even more. I think I like the CTH best with my 6xx and the LCX with my 4xx. And I did get balanced cables for both headphones to get the most out of the LCX (negating any saving on the amp!), but all my amps have XLR out so it makes things easier. Curious what tube you might point me to if I wanted to try something else?

Feb 27, 2021