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Tube preamp and a solid state power amp
- Thread starter rkidLG
- Start date
@rkidLG according to the owners manual, the input impedance of your sunfire grand is 24kOhm via RCA and 15kOhm via balanced XLR, which is low for anything thats not a pro audio power amp. thats gonna restrict you from usin classic vintage tube gear and some modern tube gear as well with higher output impedance.
a tube preamp is an excellent way to audition tube audio.
whats your budget, @rkidLG ? do you need a preamp with a built-in phono?
a tube preamp is an excellent way to audition tube audio.
whats your budget, @rkidLG ? do you need a preamp with a built-in phono?
N0rt0n
Super Member
I had a Counterpoint NPS-400 for many years that was a Hybrid Amp. Tube input and Rectifier and Solid State Output. Where do you see that fit in as for loss of sonics. I loved the sound.
PakProtector
AK member
A mu-follower current regulator can deliver very low output impedance when used as the plate load. Take a 6AH4 triode, running 25 mA, and with a 5 uF ASC polypropylene motor run output cap, at 1 kHz, the output Z was 32 ohms. Thirty two. No missing zero... 
I think that pretty much will not be offended by a 10k Ohm input Z of a SS amp. or even a 5kOhm load.
Douglas
I think that pretty much will not be offended by a 10k Ohm input Z of a SS amp. or even a 5kOhm load.Douglas
I decided to keep it solid state. I went with a Parasound P5 as it has a lot of features I am looking for and is a massive upgrade from my prior preamp. I considered a couple other tube preamps but thought it was best to stay with solid state due to similar reasons you mentioned. Thanks for your help!
Long ago I had a Sunfire Cinema Grand IV in my theater system and, while it was great for Dolby Digital theater content, I really didn't like it for 2-channel music. I've had that experience with a few Dolby Digital preamps, not sure why, but that has been the case. Assuming this is primarily for 2-channel music, I suspect you will be happier moving from the Sunfire to a 2-channel preamp (tube or SS). Don't have any specific preamps to recommend though.
I am running repaneled and recapped Martin Logan sl3s. Sunfire amps are extremely popular in the Martin Logan community and I’ve found a lot of enjoyment in the amp. I’m in the process of getting it recapped as well. It is tough to find a powerful amp that is capable of running Martin Logan’s that isn’t outrageously priced. I’ll keep my ears open for anything I may like more though
I am running repaneled and recapped Martin Logan sl3s. Sunfire amps are extremely popular in the Martin Logan community and I’ve found a lot of enjoyment in the amp. I’m in the process of getting it recapped as well. It is tough to find a powerful amp that is capable of running Martin Logan’s that isn’t outrageously priced. I’ll keep my ears open for anything I may like more though
Sorry -- the confusion is on my side. I didn't realize the Emotiva was the preamp and the Sunfire was the amp! When I hear Sunfire Theater Grand -- I automatically think A/V preamp and not amp. I'm sure your Sunfire amp is fine. It's only the Sunfire A/V preamp that, like many DD preamps, wasn't ideal for 2-channel music.
I’ve really enjoyed the sunfire. But yeah the power amp not a pre. I imagine the emotiva is holding back my system a bit. Can’t wait to use the Parasound when it comes in. I’ve also not heard great things about the Sunfire preamps. There are some cool vacuum tube pres they made that are nice but are extremely expensive and hard to find.
oh wow. do you happen to have a schematic handy for this 6AH4 mu-follower circuit?A mu-follower current regulator can deliver very low output impedance when used as the plate load. Take a 6AH4 triode, running 25 mA, and with a 5 uF ASC polypropylene motor run output cap, at 1 kHz, the output Z was 32 ohms. Thirty two. No missing zero...
Douglas
FWIW, that particular board has significant design problems and doesn't actually work. There are several issues, including inherently high DC offset and less than ideal RIAA. I replaced the junk caps with polypropylene (used electrical-grade silicone to attach them to the board) and made several changes to the values and overall design. I "negged" the seller, something I haven't done in many years. Yes, let's get back to tubes, talking about this Chinese junk makes me sad...
maxhifi
Addicted Member
Ah, but it looks better than perf-board and you'd never be able to make it for what it costs. Good phono stages are expensive, those boards may not be usable as-is but if you just consider the board itself as what you're paying for and not the parts or crappy clone design, it isn't a bad starting point.
A mu-follower uses a cascode CCS or gyrator as a plate load.
Hybrid Mu-follower Output Impedance
Where to start? Well, I often get the question “what is the output impedance of the gyrator circuit?”. My response has always been “it gets close to 1/gfs as a good approximation&…
www.bartola.co.uk
The CCS or gyrator can made with mosfets, tubes or other devices. I like a fairly simple cascode pair using depletion mode mosfets.
ah...im vaguely familiar. ill be goin thru this soon.A mu-follower uses a cascode CCS or gyrator as a plate load.
Hybrid Mu-follower Output Impedance
Where to start? Well, I often get the question “what is the output impedance of the gyrator circuit?”. My response has always been “it gets close to 1/gfs as a good approximation&…
The CCS or gyrator can made with mosfets, tubes or other devices. I like a fairly simple cascode pair using depletion mode mosfets.
in these links is the 6AH4 mu-follower circuit as douglas @PakProtector described?
is that a no? sounds like a no.
If you want a schematic, then it's a no. It isn't very hard to choose an operating point on the curves and draw a horizontal load line through it. The ccs determines the biascurrent and you pick a cathode resistor to give the cathode voltage you need at the bias current.
one thread about a 6AH4 line stage.
www.diyaudio.com
one thread about a 6AH4 line stage.
6AH4 Preamp..A great option for line stage
Started researching a good line stage to match these 1625 power amps. After a lot of reading, stumbled on the low mu approach. The more I read, the more it made sense. So, found this design by Thomas Meyer, which I found intriguing. Was initially going with a 12B4, but I love the sound from...
thank you for answering. of course i do. thats why i asked for it.
oh man, i was just reading this and the vinyl saviour build thread they reference!one thread about a 6AH4 line stage.
6AH4 Preamp..A great option for line stage
Started researching a good line stage to match these 1625 power amps. After a lot of reading, stumbled on the low mu approach. The more I read, the more it made sense. So, found this design by Thomas Meyer, which I found intriguing. Was initially going with a 12B4, but I love the sound from...
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Andre Garcia
“WITHOUT MUSIC, LIFE WOULD BE A MISTAKE”
Thanks for the kind words.
I made them, Rhea is a fantasy name I put to my audio stuff. Solid wood, except the front. Eminence T, W and Electrovoice M.
Andre.