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    Building, troubleshooting and testing of these amplifiers should only be
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    the safety precautions around high voltages.

Tripath TA2020 + 6N3 Tube buffer

Hi everyone,

Totally new to tubes and preamps - Matter of fact, I have no idea what i'm doing here.

I managed to assemble an TA2020 chipamp (from 41hz.com) which I've used for a portable boombox last year. I have just got an 6N3 preamp/tube and wondered if I could use it together with my chipamp to either "boost" or enhance the sound quality?! - If this is the case, then i have a couple of questions I hope you could help me with:

- How should I connect the two of them?
- The chipamp is powered by a 12V battery - should the 6N3 be separately powered as well?

If anyone would be so kind to make a drawing of how they should/could be connected, it would be much appreciated.

Thanks in advance for helping a noob.

Kind regards,
Tobias

Pictures
The amp
http://postimg.org/image/v6euhakcv/
The tube
http://postimg.org/image/6p1obkadb/
 
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Thanks, jazbo8..

I would actually rather use the amplifier for the sound source, so that the tube is "after" the input.. Would that work, or does that just make no sense?

I still seem to have some troubles with the wiring because the amp has no input (only 2 channels output), where the tube has 2 channels input and 2 channels output..

The obvious thing to do (as I see it) is:
"Amp; output" -> "Tube; input" -> "Tube; output" -> "Speakers".

Am I way wrong?
 
Thanks, jazbo8..

I would actually rather use the amplifier for the sound source, so that the tube is "after" the input.. Would that work, or does that just make no sense?

I still seem to have some troubles with the wiring because the amp has no input (only 2 channels output), where the tube has 2 channels input and 2 channels output..

The obvious thing to do (as I see it) is:
"Amp; output" -> "Tube; input" -> "Tube; output" -> "Speakers".

Am I way wrong?

You have to get the basics right first.

The buffer handles only small signal levels (line level) and is your preamp (basicly your volume control).

The 41hz amp is your power amplifier and brings your line level signal up to enough power to drive your speakers.

Running a power amplifier into a pre-amp is a recipe for instant death for the preamp.

So the correct signal chain is signalsource-buffer-poweramp.
 
Alright, thanks.. As said i'm really first learning here, why i know my basics are really insufficient..

So, what I should do is signal source->buffer->(via jack-in) amp->speakers?

As for power supply, can I connect my 12V battery directly to the PCB of the buffer? And should both the amp and the buffer be powered, or how does that work?

Thank you for bearing with me and my lack of knowledge :)
 

jazbo8

diyAudio Moderator Emeritus
2011-01-05 8:34 am
In Transient
"source->buffer->(via jack-in) amp->speakers?"
That is correct.

But given your in-experience, it may not be a good project for you to start with. There are hybrid kits that are already set up the way you want - using the tube as a buffer for the TA2020. They don't cost much at all, so perhaps you can get that instead, but to be honest, since the tube is simply being used as a buffer, often without any gain at all - so I am not sure you will really hear any difference at all - especially if you run the tube at low voltage.

Jaz
 
Yeah, I've seen those hybrid kits, but most of doesn't run off of 12V. - And as i'm using the setup for a portable system, i also have to have the battery life span in mind.

I got the 6N3 from friend of mine. He bought it assembled and tested, so i don't have to do any soldering or anything. Sadly he's not able to help me with my project, which is why I turned to you fine gentlemen..

Jaz, you're having your doubts whether it will do a difference as it'll only be used as a buffer? But it should theoretically still provide gain and extra power for the output, or not?

As for the power supply, do you know how I could power the signal off? Battery in one end, or battery on Amp AND Buffer?
 
That buffer needs AC so you need a transformer or an AC wallwart with enough current capability.

It may have a voltage doubler circuit on it and then yo got more then 12v present on the board.

So there may be a shock hazard even when feeding with low voltage.

I encourage people to explore and learn but if you´re a total newbie perhaps it´s a good idea to get help from someone more experienced.
 
Yeah, I've seen those hybrid kits, but most of doesn't run off of 12V. - And as i'm using the setup for a portable system, i also have to have the battery life span in mind.

I got the 6N3 from friend of mine. He bought it assembled and tested, so i don't have to do any soldering or anything. Sadly he's not able to help me with my project, which is why I turned to you fine gentlemen..

Jaz, you're having your doubts whether it will do a difference as it'll only be used as a buffer? But it should theoretically still provide gain and extra power for the output, or not?

As for the power supply, do you know how I could power the signal off? Battery in one end, or battery on Amp AND Buffer?

A buffer in it´s true meaning is unity gain = 0 or sometimes a bit less then zero amplification.

What you´re after with a buffer is a volume control and the a capability drive your amp.
 

jazbo8

diyAudio Moderator Emeritus
2011-01-05 8:34 am
In Transient
Jaz, you're having your doubts whether it will do a difference as it'll only be used as a buffer? But it should theoretically still provide gain and extra power for the output, or not?

As for the power supply, do you know how I could power the signal off? Battery in one end, or battery on Amp AND Buffer?

I should qualify my statement, since the TA2020 does not really need a pre-amp, in many hybrid designs, the tube is run as a cathode follower, with less than unity (<1) gain, in fact, it should sound exactly the same as the input given the 100% negative feedback, it's as colorless as a tube is going to get... For a placebo effect, put an orange LED under the tube and "light it up", so you can get that nice warm "tube" glow.:D

Of course, you don't have to use the cathode follower configuration, in which case, you can amplify the signal then attenuate the output, before the TA2020 so it is not over-driven.

May I ask what is the application for this hybrid amp? Is it for portable use? If so, the whole thing can be run off battery, or as it has been suggested, run off an AC-DC power supply, either way will work. Take a look at the links I provided, and you can see both scenarios.

Jaz
 
That buffer needs AC so you need a transformer or an AC wallwart with enough current capability.

It may have a voltage doubler circuit on it and then yo got more then 12v present on the board.

So there may be a shock hazard even when feeding with low voltage.


May I ask what is the application for this hybrid amp? Is it for portable use? If so, the whole thing can be run off battery, or as it has been suggested, run off an AC-DC power supply, either way will work. Take a look at the links I provided, and you can see both scenarios.

Yes it is for a portable system..
So is it possible to power the buffer with a direct wiring between buffer and battery? As far as I know 12V truck batteries are DC, wouldn't it be necessary, as flatheadmurre mentioned, to use a inverter or DC-AC transformer? Or could it work by simply connecting battery directly to the PCB?

Of course, you don't have to use the cathode follower configuration, in which case, you can amplify the signal then attenuate the output, before the TA2020 so it is not over-driven.

Would this make sense in proportion to louder, smoother or just better sound quality?
 
Do you have a schematic for the buffer ?

It says 12v AC on it and that gives in ballpark of 16-17v DC if not voltage doubler is used then you got even higher dc voltage.

So battery power for the buffer is possible but you have to find out what voltage you really have in the circuit and perhaps stack a couple or more batteries for the right voltage.

A good buffer ads nothing to the sound and the output power is set by the power amp.

If you want to shape the sound with something like a equalizer you need more stuff adding more gain to get overdrive makes it an effectbox and not an amplifier.
 
I got this schematic off of another thread: View image: IMG 0002. Should be the same..

Specs:
input voltage:AC 12V

Frequency response : 10Hz - 40KHz + / -1dB

Total harmonic distortion THD: > 0.005%

Signal noise ratio S/N: 95dB

Gain: ≈0dB

If you want to shape the sound with something like a equalizer you need more stuff adding more gain to get overdrive makes it an effectbox and not an amplifier.

No, it's not like i wanted to shape the sound or anything fancy - Just hoped that by using this buffer i could get more/better sound out of my speakers, to be honest. But that seem not to be the case?
 

jazbo8

diyAudio Moderator Emeritus
2011-01-05 8:34 am
In Transient
I got this schematic off of another thread: View image: IMG 0002. Should be the same..

Specs:
input voltage:AC 12V

Frequency response : 10Hz - 40KHz + / -1dB

Total harmonic distortion THD: > 0.005%

Signal noise ratio S/N: 95dB

Gain: ≈0dB



No, it's not like i wanted to shape the sound or anything fancy - Just hoped that by using this buffer i could get more/better sound out of my speakers, to be honest. But that seem not to be the case?

Just as I thought, the buffer is configured as a cathode follower, in fact, the specs tell you that there should be no difference in sound whatsoever, given its low distortion and 0dB, i.e., no gain. So it will not make the sound "fuller" if that is what you are thinking of. As suggested, an EQ will have much more tonal shaping capability, or even diode clipping if you are after a more distorted sound. For other ideas, you can check out some solid-state amplifiers from Marshall, VOX, etc. which all use chip amps as the power output, with the tone shaping done in the preamp stages.

How do you plan to supply the voltages for the TA2020 and the buffer boards?
DC boat battery -> DC-AC Inverter -> AC-DC power supplies that came with the units? Doesn't seem too portable, no?

Jaz
 
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I guess you guys are right. I think i'll just drop the idea of the two of them together for this application.

But as i'm still wanting to get more and/or better sound out off of my system, having in mind that the battery usage can't be too high, what could i do in this case? - Should i get a more powerful amp, or could I use another preamp to give the sound a boost?

I really appreciate that you're taking your time helping me..
 
I´m not really shure what kind of PA speakers you have but 2x25w for a 2.1 PA system is in my world underpowered.

I´m not really shure how you manage to hook up a 3 speaker setup to the amp6 correctly.

Get another mono amp for the sub and a crossover then your set for summer party.

Find a nice kit for a poweramp to go with the buffer for indoor use.

And don´t get dicouraged if we sometimes sound a little hesitating, we just want to be sure no one gets hurt in the progress.
 
I´m not really shure what kind of PA speakers you have but 2x25w for a 2.1 PA system is in my world underpowered.
Yeah, follow you on that one. - Would it make sense using a Class D amp for the Speakers and the Amp6B for the sub, with a cross between them?

When it comes to crossovers I have (also) no experience why I'll prefer to buy an assembled one. But to be honest, I have no clue what i'm looking for. What do i have to be aware of? - passive crossover would work, right? What about slope, compatibility, Watt rating?

And don´t get dicouraged if we sometimes sound a little hesitating, we just want to be sure no one gets hurt in the progress.
.. I don't - only get more hooked on learning :)