Hello Experts/Enthusiast
I am interested in a DIY Tube-Preamp. Can someone share where should I look for circuits and guidance.
Thank you all in advance.
Cheers
I am interested in a DIY Tube-Preamp. Can someone share where should I look for circuits and guidance.
Thank you all in advance.
Cheers
I like Designing High Fidelity Valve Preamps. There's also a lot of good info on the site; worth poking around.
But what I like most of all is a good DAC straight into a good power amp: no preamp required 🙂
But what I like most of all is a good DAC straight into a good power amp: no preamp required 🙂
Many tube preamps are not universal, and must be used with compatible components.
What sources do you have: CD, FM, phono, tape? Are they tube or solid state?
What power amplifier do you have, tube or solid state?
What sources do you have: CD, FM, phono, tape? Are they tube or solid state?
What power amplifier do you have, tube or solid state?
@rayma thanks for your response. Specifically, I'm seeking a Pre-Amp design that can support 1-2 RCA inputs and 1-2 Balanced XLR inputs, with a Balanced output to my PowerAmp. These are my primary needs. As for the associated equipment, I'm currently using custom build DAC connected to emotiva pre-amp and parasound poweramp. I'm open to suggestions that might complement or enhance my existing setup.
So you are looking for a fully balanced in/out tube line stage?
Here's an example of a circuit. You could modify it in various ways.
One way is to use a conventional volume control, and if you prefer,
resistors instead of fets. The power supply could be simpler as well.
Here's an example of a circuit. You could modify it in various ways.
One way is to use a conventional volume control, and if you prefer,
resistors instead of fets. The power supply could be simpler as well.
What sources do you have.? What is their output level? Drive capability?
What is the input level of your amp, Input impedance?
Do they match, or do you need gain? How much gain if so?
What is the input level of your amp, Input impedance?
Do they match, or do you need gain? How much gain if so?
If you want a premade solution, but a kit, look at one of the Broskie designs on the Tubcad.com site. See the link below, I'm assuming you will want some gain. If you want to run balanced in and out two kits will be needed as the kits are single ended. So one board will be + and - for the right channel and the second board board + and - for the left. You'll wind up with 8 tubes (4 per channel) for a stereo balanced line stage. The Aikido 12Vac has the power supply (less transformer) right on the board. Easy peasy. My preference would be to build the 12Vac with 6DJ8 tubes rather than 12AU7s.
http://glass-ware.store.turbify.net/ailiam.html https://tubecad.com/
Cheers, Steve
http://glass-ware.store.turbify.net/ailiam.html https://tubecad.com/
Cheers, Steve
A certain amount of gain is always required for maximum output. The question is, separate the first gain stage/power supply as
an external preampllifier from the rest of the amp or not. Depending upon the application, your concept is quite sound.
I think the question then becomes, the enjoyment goal, cost factor, the level of musical quality one wishes.
For instance:
1. Separate preamplifier with basic amplifier, extra ics needed.
2. For higher quality, high quality separate preamplifier (with super channel separation) with monoblock amplifiers.
(Power supplies separated, higher cost.)
3. For even higher quality separate power supplies for each stage of preamplifier and monoblocks.
4. For even higher quality, and more expensive, separate power transformers for each stage.
5. For even higher musical quality, separate power supplies using poly capacitor filter stages. Eliminate the electrolytic filter
capacitors as much as possible. (Poly beats the heck out of electrolytic capacitors DA 0,02% vs ~7%.)
6. Other odds and ends to improve the musical quality.
I followed points 5, 6 and in a completely different world of sound. But it is expensive and physically large.
cheers
pos
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@TheGimp My audio setup includes a Streamer/DAC with OPA861 (IanCanada boards), having a max output of 4VRMS at 0dB. My power amp is a Parasound A23+ with 160W at 8 Ω and a balanced input impedance of 66 kΩ. I'm currently using an old Emotiva pre-amp that's malfunctioning and looking to switch to a Tube PreAmp. My apologies in advance if I miss anything
The chances are you might not need any gain. If that's true a cathode follower stage with a volume control with a input select switch in front of it might be all you need. Where did you usually set the volume control on your Emotiva for a satisfactory listening level?
BUT if you do need gain, the Glassware Aikido is one of the best preamps that I have ever built. I am not sure, but there may be a little play allowed depending on the tube used.
And the position of the volume control is? Maybe 9 o'clock, maybe 12 o'clock or something?
And the position of the volume control is? Maybe 9 o'clock, maybe 12 o'clock or something?
@lxnay - I currently adjust the gain at the pre-amp level and want to keep it that way. I've been reading about Aikido pre-amps. Could you share details about the power supply you used in your build?
Yes, we understand that you are using the volume knob on the preamp to adjust the volume/gain. The question that we are trying to ask is about the position of rotation of this knob when you are listening to music. So the knob can be rotated 270 degrees, getting louder when turned clockwise and softer when turned counterclockwise. At what position do you turn it to when listening to most music?
I will answer the power supply question after you have answered this question.
I will answer the power supply question after you have answered this question.
Manues,
What is your budget for a line stage? Are you prepared to buy a generic chassis and do a bit of metalworking on it? Holes for tube ventilation, switches, volume pot, jacks and the like. Budget $100 to $150 for a generic chassis from China via eBay.
What is your budget for a line stage? Are you prepared to buy a generic chassis and do a bit of metalworking on it? Holes for tube ventilation, switches, volume pot, jacks and the like. Budget $100 to $150 for a generic chassis from China via eBay.
@lxnay - Appreciate your assistance; I realize I could have been clearer in my response. Usually, I listen at about 25%-35% of the max gain