Massdrop Cavalli Tube Hybrid Amp

The white is oxide (magnesium iirc), meaning that the inside of the tube is no longer under vacuum and the contents have been exposed to air. Powering up an amp with a damaged tube is likely to kill the amp ( especially a hybrid amp ). This is the reason people in general ship amps with the tubes packed in little boxes and not plugged in although I have been guilty of this practice myself.

I have seen at least one amp die with a cracked tube ( person dropped the tube while picking it up to seat the tube in the socket, didn't check the tube after the drop , hit power and .... POOOF )

..dB

 

I'd check with our SBAF/MD guru @CEE TEE , but I'm pretty sure they'll take care of it. Have had good luck with my experience with Massdrop across the years. Cheers

 

This perfectly describes what I think happened here. I'm just hopeful that I won't have to pay import fees to Canada again for a replacement. It's like $30 every time.

 

I guess I was lucky. When I received my Valhalla II last September, after 30-40 minutes of listening I lost the right channel. After switching the tubes about, I determined that the right driver tube was dead and over the next few hours the tube (which had been dark) became transparent with a white coating near the tip. I contacted Schiit immediately and the next day (Saturday) Schiit sent me a complete new set of four tubes. Luckily the amp was fine once the bad tube was replaced.

 

You're lucky you don't live in the UK. I'm looking forward to paying import duty + import vat (20%) + handling fee! Expecting a three figure total. Eeek . Even taking that into account, I think the amp will be worth it.

I think I read somewhere that you don't pay import costs on re-returns?

 

@Resolve there is a way to get your duty/customs payments back if you end up paying more than once for the same product (ie: a replacement). It's a pain in the ass but it's definitely doable. Inquire with Customs for specifics.

 

So far massdrop support has been great with helping me deal with this. They've offered to pay for customs and send out a replacement, or provide a full refund. Very nice of them. I'm hesitant to take the replacement though because even though it sounded good... I don't want an amp that will crap out on me like that. It might be worth it to go for a balanced option instead from them like they have available right now. No tube risks... If thatst a thing.

 

Do you think this would be better than the Cayin IHA-6 for the AFO and Nightowl? I guess that's a bit of a big ask. Sorry haha. But those are my options at the moment.

 

I can say that the CTH is a absolutley fantastic amp!

..dB

 

The first section about Visible Signs seems very thorough. I guess a visual inspection before and after power up should be in the CTH SOP.

http://blog.thetubestore.com/how-to-tell-if-your-tube-is-bad/

 

Another toob noob question:
From the designer (runeight) at AdFi:

I bought a bunch of 6922/ECC88 from @shotgunshane. Would all of these qualify as "6922 equivalent"?
https://superbestaudiofriends.org/index.php?threads/tube-grab-bag-7-singles-6922-ecc88.5212/

 

Good question. Looking at the tube specs over at Frank's https://frank.pocnet.net/ indicates that the ECC88 requires a slightly higher heater current than the E88CC (aka 6922). Don't know if that would be an issue.

 

It won't - iirc it is only 30mA and these tubes are pretty much interchangeable.

I wouldn't use something like the 6B27 which draws 400mA and steer well clear of the 6H30 which needs almost an amp for the heaters - both of these tubes need a much higher B+ to operate in spec.

Think of tube rolling in the CTH akin to using the same gas in your car engine as your 2-stroke chainsaw. You wouldn't do it ( well at least I would hope you wouldn't ). The CTH is optimized for the 6922/6DJ8/ECC88/E88CC - just stick to these tubes and you will have plenty of fun and variation , do not use any tube with the same pinout , it may not kill the amp ( it may ... ) but it won't be performing the way it was designed to.

..dB

 

I surmise that 5670 family tubes with adapter would also work. They have very similar electrical characteristics to the E88CC. iFi even champion the GE 5670 as a replacement for the E88CC https://ifi-audio.com/portfolio-view/accessory-nos-6922-2/

The E288CC, on the other hand, has significantly different electrical characteristics from the E88CC despite having the same pin configuration. I have an E288CC which works nicely in Vali 2 but I won't be trying it in the MCTH !

 

no - this would be 2-stroke oil in your precious escalade

 

Thanks for the heads up @dBel84. This also completely rules out using the 6CG7 in the MCTH. This is really useful information that I hope reaches all of the folks who joined the drop.

 

Thanks. Which website did you source those data sheets from?

I will stick to the very nice Philips E88CC SQ and Valvo E88CC that I have

 

Are you saying this is true for all amps or just the CTH in particular? I don't know much about engineering so I am reluctant to enter this discussion and likely show my ignorance, but I have used both 5670 and the equivalent 2C51 tubes with adapters for months as replacements for 6922s, E88CCs, or the stock 6N1Ps in the Valhalla 2, as have many others. They work perfectly in that amp. (Indeed, Mike Moffat has stated that that is his favorite tube for the Valhalla 2.)