[Mediahound]

This is dead wrong. Dr. Cavalli himself has posted in this very thread on numerous occasions about the design of this amp, which he created collaboratively with Massdrop. Stop trolling.

What about this don’t you understand?

This is totally my design (or, more accurately, redesign of the DIY CTH), licensed to Massdrop.

 

[jrhill]

Warming up a Siemens PCC88 - very different sound to the Russian 6H23 or the original EH6922 - I wonder how many hours they take to 'come good"?

 

[Zachik]

Warming up a Siemens PCC88 - very different sound to the Russian 6H23 or the original EH6922 - I wonder how many hours they take to 'come good"?

Never tried tube rolling on the CTH, yet, but people kept saying it makes little to no audible difference...
Are you saying the Siemens PCC88 does sound audibly different than stock tube? Would you say it is a small or very noticeable difference? (and what is difference between their sound signature?)

 

[jrhill]

A 'little to no audible difference' - Ah, it depends, sorry - familiar words?

I'm using a modded HE400s with the CTH amplifier and the Ayre Acoustic QB-9 dac + the SOtM Server as the source - also use the AKG k701s and Senn 650s - the better linear power supply costs as much as the amp itself and makes a huge overall improvement (IMO, naturally!).

The difference between the Siemens and the EH6922 (to me) is the 'air' and 'detail' - it seems to be a "lighter' sound and more dynamic - the bass is very clear - the tube has only about 5 hours use so far so the sound may change a bit yet -

IMO, the EH 6922 has a heavier lower mid sound that gives it a pronounced sense of rhythm but it's not as transparent - the Russian tube was similar. I have a Mullard (or RCA, can't remember) that has a much thicker bass but blurred mids - I like a clear open overall sound with very clean bass

I'm an inveterate fiddler so modding everything is an interest - if you're happy with the basic switcher supply and your source, the change in the tube will probably only produce a small change - it's a pretty well-sorted out piece of gear

... all the best

 

[Phantaminum]

Never tried tube rolling on the CTH, yet, but people kept saying it makes little to no audible difference...
Are you saying the Siemens PCC88 does sound audibly different than stock tube? Would you say it is a small or very noticeable difference? (and what is difference between their sound signature?)

There are differences but they're not as transparent as other hybrid or full tube amps. Even though they may make small changes it may be enough of a change to warrant the purchase. Just don't go crazy buying a Siemen's Cca or E188CC that costs half of the amp for a minor change.

 

[Zachik]

There are differences but they're not as transparent as other hybrid or full tube amps. Even though they may make small changes it may be enough of a change to warrant the purchase. Just don't go crazy buying a Siemen's Cca or E188CC that costs half of the amp for a minor change.

Even the Siemens PCC88 are not very cheap at approx. $100 / pair or $70 for 1...

 

[Phantaminum]

Even the Siemens PCC88 are not very cheap at approx. $100 / pair or $70 for 1...

Yeah, the 6922 and equivalent tubes have stabilized in price but have shot up in last few years. That's why I asked earlier in this thread about an adapter and 5670 tubes. The 5670 and equivalent tubes have a wider sound stage than the 6922s and are cheaper while still sounding great.

The biggest difference in sound came from the 6c8gs. Depending on your headphone, these tubes throw out a huge soundstage. It really gives you a taste of what a TOTL tube amp brings to the table at a reasonable price compared to higher end 6922s.

I've been using this combo since April and haven't ran into issue. This doesn't mean I may never run into issue by not listening to the Dr.Cavalli. For me the enjoyment outweighs the risks.

 

[Zachik]

Yeah, the 6922 and equivalent tubes have stabilized in price but have shot up in last few years. That's why I asked earlier in this thread about an adapter and 5670 tubes. The 5670 and equivalent tubes have a wider sound stage than the 6922s and are cheaper while still sounding great.

The biggest difference in sound came from the 6c8gs. Depending on your headphone, these tubes throw out a huge soundstage. It really gives you a taste of what a TOTL tube amp brings to the table at a reasonable price compared to higher end 6922s.

I've been using this combo since April and haven't ran into issue. This doesn't mean I may never run into issue by not listening to the Dr.Cavalli. For me the enjoyment outweighs the risks.

So, if I am going to give it a try:
1. Do I need 1 or 2 socket savers? At some point couple pages ago I got confused by the mention of 2... was it because a seller was selling them in pairs, or do I need 2 to get sufficient elevation for the tube to fit?!
2. I recall your best / most recommended 6c8g was very pricey... what is your 2nd favorite? I definitely LOVE bass, and prefer smooth sound compared to hyper detailed. I like tubey sound!
3. I believe the eBay link to the adapter is sold out, and I do not want a cheap Chinese substitute that would fry my amp... any recommendation for active sellers? Does not have to be eBay...

Thanks!!

 

[Phantaminum]

So, if I am going to give it a try:
1. Do I need 1 or 2 socket savers? At some point couple pages ago I got confused by the mention of 2... was it because a seller was selling them in pairs, or do I need 2 to get sufficient elevation for the tube to fit?!
2. I recall your best / most recommended 6c8g was very pricey... what is your 2nd favorite? I definitely LOVE bass, and prefer smooth sound compared to hyper detailed. I like tubey sound!
3. I believe the eBay link to the adapter is sold out, and I do not want a cheap Chinese substitute that would fry my amp... any recommendation for active sellers? Does not have to be eBay...

Thanks!!

1. You only need one socket saver. That will give you enough height for the 6c8g adapter. You can go with one made from China, which is cheap, or preferably one from Tube Monger (recommended).

2. My favorite tube is the Tung-Sol and yes it's expensive compared to the other tubes. Instead grab a Ken-Rad, RCA, or Sylvania. Any of those tube NOS singles can be found from $15 to $40. For your requirements I'd suggest the RCAs. Give them minimum 40 hours of burn in so they can really show their chops.

3. The socket saver is what burned out the amp. Tube Monger socket savers are what I'd purchase. The 6c8g you'll have to get from China. I don't think anyone in the US makes them but I've purchased several adapters from this eBay seller without having any issues.

Link to the 6c8g adapter: https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/191554107223

 

[Zachik]

2. My favorite tube is the Tung-Sol and yes it's expensive compared to the other tubes. Instead grab a Ken-Rad, RCA, or Sylvania. Any of those tube NOS singles can be found from $15 to $40. For your requirements I'd suggest the RCAs. Give them minimum 40 hours of burn in so they can really show their chops.

When looking for any of those tubes - what should I look for?! Any specific years? Any specific getter? Would ANY RCA or Tung Sol or Ken-Rad do?
Long list of 6c8g on eBay.... Need something to focus my search

 

[Phantaminum]

When looking for any of those tubes - what should I look for?! Any specific years? Any specific getter? Would ANY RCA or Tung Sol or Ken-Rad do?
Long list of 6c8g on eBay.... Need something to focus my search

I'll shoot you a PM later today.

 

[Ameloblast]

Anyone coming from Schiit Vali 2? Is this a significant upgrade and what are the sonic differences? thanks!

 

[Ameloblast]

Welp, as soon as I saw this dropped as a daily with immediate shipping, I couldn't help myself. Ugh. My wallet is going to hate me. Looking forward to comparing it with my Vali 2!

What are your thoughts on the CTH compared to Vali 2? thinking of getting the CTH and was wondering if its a significant enough upgrade.

 

[imparanoic]

Just wondering, is the 6922 valve easy to replace? Readily available?

 

[Guidostrunk]

Absolutely.

Just wondering, is the 6922 valve easy to replace? Readily available?