They sound amazing with the caldera. Really brings an amazing boost to the mids. I’m using a 6v6 fivre and rca black leg 12AU7s
Cayin HA-3A, a Compact 6V6s Transformer-coupled Tube Amplifier
- Thread starter Andykong
- Start date
Great combo, as long as you have a good DAC and nail the NOS tube set. Bendix 6V6, Mullard M8136 12AU7 did it for me. Rectifier makes the smallest difference but the GE sounds a bit clearer to me than the stock RCA.
Louisiana
500+ Head-Fier
Same here, but instead of the Brimars, i use a pair of these:
https://tubeworldexpress.com/products/12au7-ecc82-rt-radio-technique-france-long-plates-1958-1959-v1
For my ears, these are the most holographic 12AU7 tubes i ever listened to.
The link doesn't work for me. Does it for you? Can you pass the tube type and brand instead? Thanks
Louisiana
500+ Head-Fier
Yes it works, but as you wish:
I don’t bought the tubes from Tubeworld, but these are exactly the ones I use.
grant0317
Head-Fier
Mullard 6v6gt extended the bass very nicely vs stock tubes. Rectifiers seem to be whatever you can get your hands on. I've found raytheon and ge 25ax4gt tubes, but there doesn't seem to be a whole lot left out there.
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NJoyzAudio
100+ Head-Fier
Honeypot
Congrats on your purchase and welcome to the forum as an owner!
There are several here who use the Caldera Open back on the HA-3A and have reported great synergy
At Can Jam SoCal I was able to hear the Caldera on an Cayin Amp (looking at my notes, pretty sure it ws a HA-3A and not the 6A) and can tell you it was great.
I personally have the Meze Elite on the HA-3A and can confirm that paring is also very good, and even with several IEM's its still a great pairing.
As Betula mentioned pairing a great DAC to this amp will take to an even higher level of sound.
There are many good recommendations on the thread but I can put in a thumbs up for the Musican Pegasus R2R (normally an AKM DAC user, but the Cayin Tube amps with R2R DACs really sound great and capture that tube sound), but have seen several here really enjoying the Holo Spring DAC's, and the Denafrips DACs.
For 12AU7 tubes, I see many have given you some recommendations, will throw out there NOS Amperex Bugle Boy's, but will really suggest looking at the E80CC tubes, as on the HA-3A IMO take the sound to another level yet. These tubes (12AU7/E80CCs) will influence the sound the most.
Renex had a great chart earlier in the thread with a nice quadrant of how they influence the sound.
For Power tubes, I've been rotating between Mazda 6V6G, and Mullard 6V6G (ST type) and the Bendix 5992's
I do have NOS 50's and 60's Brimar, RCA and some RAF Blackglass ST type tubes, but find I keep going back to the 3 above. Just a much more balanced sound with still a hint a little more towards bass/warmness for me.
As to the rectifiers
I found someone who had a nice selection and wanted to sell all 10 at the same time, and not break up the set of 25AX4GT's they had,
It does influence the sound but not as much as the pre/driver tubes do.
Via this purchase I've tried the NOS RCA Black and Grey Plate, GE Black and Grey Plate, Raytheon Grey Plate and Sylvania Black Plate rectifiers. I'm finding I keep rolling back to the Sylvania and have left it there now for several months after initially rolling through all of them
I've got 10 of these tubes at a great price, all NOS and probably set for life (and have mentioned here before open to selling some of them). I still see the GE, Sylvania and Raytheon rectifiers at different reputable sellers on line so no rush to get additional rectifiers
This forum has the nicest group of Head-Fiers and all will lean in to help, just ask
Hope this information helps, and all I write above is IMO and YMMV
Again, Welcome to the HA-3A forum!
Yes it works, but as you wish:
I don’t bought the tubes from Tubeworld, but these are exactly the ones I use.
Thank you all for the answers! I definitely have some cool 12au7 tubes already, but will give some of these a try. Always welcome new ideas and pairings.
I already own a R2R DAC. So great to hear hehe.
The ha-3a is going for the caldera while still waiting for the atrium open to come, that will hook with the otl I've got.
For now using the otl as preamp for my SS and hooking it with the caldera. So I get the warmth of tubes and final amplification and impedance matching of the SS. It works great.
Still doubtful about splitting the signal via RCA splitter (maybe more EMI) vs dedicated box switch (more cash box+cable). For now got these two:
Edit2: I could get some Mazda 6v6gt
Can't find any Mullard or Bendix.
Found some nice fivre, amplitrex and electronique Phillips.
Ideas?
Driver tubes are going to be 12au7 Mazda or Mullard 12au7 10m.
Thanks in advance
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Welcome home boy
Now waiting for some nice nos tubes while trying the default ones. A little bit bright to my taste.
The mullards 12au7 10m and the 6v6gt will help I believe.
By the way, which impedance setting you use with caldera?
It's rated at 60ohm and first it's from 8-64. I've got them in the first setting. Tried middle. I don't know yet...
Now waiting for some nice nos tubes while trying the default ones. A little bit bright to my taste.
The mullards 12au7 10m and the 6v6gt will help I believe.
By the way, which impedance setting you use with caldera?
It's rated at 60ohm and first it's from 8-64. I've got them in the first setting. Tried middle. I don't know yet...
Settled on mid-impedance with the Caldera. Low is just a bit soft and high is too harsh to me.Welcome home boy
Now waiting for some nice nos tubes while trying the default ones. A little bit bright to my taste.
The mullards 12au7 10m and the 6v6gt will help I believe.
By the way, which impedance setting you use with caldera?
It's rated at 60ohm and first it's from 8-64. I've got them in the first setting. Tried middle. I don't know yet...
In theory... recall that since Calderas are planars and not dynamic drivers its frequency response shouldn't change on the different impedance settings on the amp and therefore some will use the highest, most powerful setting available unless there's a noise floor issue.Welcome home boy
Now waiting for some nice nos tubes while trying the default ones. A little bit bright to my taste.
The mullards 12au7 10m and the 6v6gt will help I believe.
By the way, which impedance setting you use with caldera?
It's rated at 60ohm and first it's from 8-64. I've got them in the first setting. Tried middle. I don't know yet...
How is that possible? Even for a planar? It's because of being OTC? Excuse my ignorance.
This has been my experience as well - I find it's pretty subtle (and volume needs to be adjusted slightly to match) but medium feels like the sweet spot on Caldera.
Good question! I don't really understand the science behind it either but from googling around that does seem to be the consensus opinion. @GoldenSound Does this sound correct - The frequency response of planar headphones is generally not affected by the different impedance settings on an amplifier?
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Correct
The output impedance of an amplifier changes the FR of headphones because of the varying impedance curve of the headphone. So for many dynamic driver headphones which typically have a rise in impedance at low freqs, a higher output impedance will cause an increase in bass.
But planar magnetics have a flat impedance curve vs frequency, and so they will not change in FR as the output impedance changes. Any differences in sound are just due to other factors like distortion and how easy/hard a time the amp is having actually driving the load.
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