Frequently Asked Questions about Tripath-based amplifiers
What Tripath-based amplifiers are available?
- AMP1 ~$51 USD
- AMP1-B ~$61 USD
- AMP2 ~$97 USD
- AMP3 ~$32 USD
- AMP4 ~$58 USD
- AMP5 ~$84 USD
- AMP6 ~$46 USD
- Class-t-amp-2020-m ~95
- Class-T-Amp-2020-m-mk2 ~130
- Fenice20 ~55-72 (no longer available)
- Sure Electronics 2*15 watt @ 4ohm, TA2024 D-class Audio Amplifier Board ~$20 USD
- T20 ~$250 USD
- T20 U ~$270 USD
- SI 5066 T-Amp ~$39 USD (no longer available, replaced by Gen 2)
- SI 5065 T-Amp Gen 2 ~$79 USD
- SI 5062 Super T-Amp ~$139 USD
- Virtue ONE (24v/60w std psu) ~$269 USD
- Virtue TWO (30v/90w std psu) ~$379 USD
- 130w power supply upgrade ~$119-$149 USD
- Mouse (kit, standard) ~$319 USD
- Mouse (assembled, standard) ~$349 USD
- Mouse (kit, upgraded) ~$369 USD
- Mouse (assembled, upgraded) ~$399 USD
What amp is going to suit my needs best?
- This depends on your system, needs, and tastes. Some of these amp designs are physically quite small (power supply aside), and being efficient they require less cooling, so they can be used in places other amps can't. (Future opinion section?)
- Refer to the table below.
Where can I get it?
- Most amplifiers can be bought at their respective websites. For the Sonic Impact amps, you will need to search the internet for the best prices. The Trends Audio basic T-Amp and modification kits may be purchased from [AudioMagus]. Virtue Audio amplifiers may be purchased from [Virtue].
How much is it?
- For the most up-to-date pricing information, please refer to the product's website.
How do I assemble it without killing it, the rest of my gear, and myself?
- Read up on soldering and circuit design.
- Triple-check your work.
- Ask questions on the forum.
Can the amps be bridged for more power?
- No. Most of the Tripath-based amps here on this forum are already bridged. No further bridging or paralleled operation is possible.
How much power does the amp put out?
- Varies with chip and with amp design. But generally, not much. The largest amp designs are several hundred watts into 4 ohms (at relatively high distortion (e.g., 1%)). High-quality operation (e.g., low distortion and some headroom to account for musical transients) is typically 70% or so of max power. The Tripath chips TA2024, TA2020 and TA2021B are all rated for about the same power. You can expect about 13 watts RMS into 8 ohms. This will vary a little with power supply voltage and current. The Winsome Labs amplifier uses two TP2050 chips for around 40 watts per channel. Apogee, which was bought by ST, made the TP2050 chips. The Virtue TWO uses the DDX2200 power chip which is theoretically capable of more than 200 watts in mono mode. 41Hz has models that use ST power output chips with even higher power.
What size power supply do I need?
- Not very large as these amps are very efficient. For most of the currently available amp designs, at least 12 volts, 1.5 Amps, depending. Some of the 41Hz amp designs want much larger, mostly balanced, power supply voltages (e.g., +/- 65V DC). It is best not to run the Sonic Impact over 13V, and a heatsink is a good idea at that voltage. Some of the 41Hz amp designs, for instance AMP6, have a built-in power supply. A 3 to 5 amp regulated supply is typically plenty. The amps typically draw about 300mA with a musical signal -- with many speakers. Some units are supplied with full power supply.
Can I run the amp on battery power, e.g. SLA? What size SLA?
- Yes. Most of the common Tripath amp designs run well on 12V batteries. A 7Ah battery is a reasonable size. There is no reason to prevent experimenting with your car battery. It's physically "too big", but, hey, it's free to experiment with.
Why does my Sonic Impact lack bass?
Is this a digital amp? Can it be connected directly to a digital signal?
- No. These are class-D amps, which use high-speed switching in a manner which reminded some of digital circuity. They are entirely analog: analog inputs, analog outputs. However, class-D has many advantages over amplifier design classes A and AB. The most important is high efficiency; these amps require smaller heatsinks (sometimes even none), smaller power supplies for equivalent audio output, etc. But note that however efficient, there will be some cooling requirement -- varying with the application. If it is not met, the Tripath chip or some other component will overheat and may be damaged or destroyed. Most importantly, of course, many of the Tripath-based Class-D amp designs have really superb sound quality within their limits (heat, voltage, clipping, etc.).
How do I remove the case of the Sonic Impact?
- Remove the little rubber feet on the bottom. There's a small screw under each. And also 2 screws in the battery compartment. There are screws that hold the variable resistor in place under the volume pointer/knob.
Which input cap is best? What size cap do I need?
- No one has yet to establish a best cap. Any good metalized film or film/foil cap will make you happy. Some users have reported preferring electrolytic cap, such as Blackgate, for more bass impact. A value of 2uF or 2.2uF is as large as you need. Voltage can be as low as 5V. Bigger sizes, say 4 to 10uf, will definitely give a big switch-on thump.
- The input capacitor will, in conjunction with the input resitor create a High Pass Filter(HPF). It is this filter that has an effect on how low the bass response is on the amplifier. You can calculate the -3db point of this filter with an equation or use this online calculator. https://www.justblair.co.uk/tripath-2024-gain-calculator.html
- A DC null circuit is also a good idea, see page 11: [1]
Do I really need an input cap?
- Yes, you do. The input cap is essential to the proper functioning of these amps. Without it, you will likely get massive DC offset, thus ruining your speakers, the amp and possibly other gear.
Do they really sound that good?
- Yes! Properly implemented, these amps are phenomenal!
What are the specifications of the Tripath based amplifiers?
| Amplifier | Chip | THD+N/Power/Load | THD+N/Power/Load | Outputs | Bridgeable | Supply Voltage (Range) |
| AMP1* | TA2022 | 0.1%/2x90W/4ohm | 0.1%/2x60W/8ohm | 2 Single Ended | Yes | +/-31V (+/-12V to +/-36V) |
| AMP2* | TK2350 | 0.1%/2x190W/4ohm | 0.1%/2x100W/8ohm | 2 Single Ended | Yes | +/-45V (+/-15V to +/-65V) |
| AMP3* | TA2021B | 0.1%/2x15.5W/4ohm | 0.1%/2x9W/8ohm | 2 Bridged | No | 14.2V (8.5V to 14.6V) |
| AMP4* | TK2050 | 1%/2x35W/6ohm | 0.01%/2x35W/8ohm | 2 Bridged | No** | 30V (10V to 36V) |
| AMP5* | TA2022 | 0.1%/2x90W/4ohm | 0.1%/2x60W/8ohm | 2 Single Ended | Yes | +/-31V (+/-12V to +/-36V) |
| AMP6* | TA2020 | 0.1%/2x11W/4ohm | 0.1%/2x7W/8ohm | 2 Bridged | No | 13.5V (8.5V to 14.6V) |
| Class-t-amp-2020-m* | TA2020 | 0.1%/2x11W/4ohm | 0.1%/2x7W/8ohm | 2 Bridged | No | 13.5V (8.5V to 14.6V) |
| Fenice20 | TA2024 | 0.1%/2x11W/4ohm | 0.1%/2x6W/8ohm | 2 Bridged | No | 12V (8.5V to 13.2V) |
| Charlize | TA2020 | 0.1%/2x11W/4ohm | 0.1%/2x7W/8ohm | 2 Bridged | No | 13.5V (8.5V to 14.6V) |
| Michael Mardis TA-10.1 | TA2024 | 0.1%/2x11W/4ohm | 0.1%/2x6W/8ohm | 2 Bridged | No | 12V (8.5V to 13.2V) |
| SI 5066 T-Amp | TA2024 | 0.1%/2x11W/ohm | 0.1%/2x6W/8ohm | 2 Bridged | No | 12V (8.5V to 13.2V) |
| SI 5062 Super T-Amp | TA2024 | 0.1%/2x11W/4ohm | 0.1%/2x6W/8ohm | 2 Bridged | No | 12V (8.5V to 13.2V) |
| Trends Audio-10.1 | TA2024 | 0.1%/2x11W/4ohm | 0.1%/2x6W/8ohm | 2 Bridged | No | 12V (8.5V to 13.2V) |
| Virtue ONE | 2 x TP2051 | 0.01%/2x100W/4ohm | 0.01%/2x50W/8ohm | 2 Bridged | No | 30V |
| Virtue TWO | 2 x DDX2200 | 0.01%/2x100W/4ohm | 0.01%/2x50W/8ohm | 2 Bridged | No | 30V |
| Winsome Mouse | 2 x TP2050 | 0.01%/2x45W/4ohm | 0.01%/2x33W/8ohm | 2 Bridged | No | 30V SMPS included |
Note 1: THD+N/Power/Load and Supply Voltage specifications were taken from the Tripath data sheets for the respective chip.
Note 2: * These amplifiers are kits that must be assembled (soldering skills are required).
Note 3: ** Depending on the implementation, AMP4's bridged outputs can be paralleled to drive a 4-ohm load.
What type of power supplies work well with Tripath Amps?
- Switching-Mode Power Supplies (SMPS) give excellent results because they deliver constant, well regulated voltage. Batteries can give explosive current bursts but voltage may sag or change.
- For voltage, amperage, and wattage, refer to the table above.
- For the Ideal Voltage, the First Voltage is a good start.
What default power connector size is used for the SI 5066 T-Amp?
- 2.1mm internal diameter with the outside the ground and the inside positive.
What is the difference between Single-Ended and Bridged?
- [SINGLE-ENDED AMPLIFIERS VERSUS BALANCED OUTPUT]
- In general, the bridged chips have been known for better sound quality. The reasons may have to do with greater power output and so less clipping. Class-D amps clip in a particularly nasty way, more dangerous to tweeters and such than most amps. These are said to sound like tube amps, but they are certainly not as 'soft clipping' as good tube amps.
Why does the Tripath website not recommend the TA2020?
- The TA2020 was discontinued because it's a through-hole package device. It's cheaper and easier to handle and mass-produce boards with surface-mount parts - e.g., the TA2024, TA2021B, etc. There was nothing wrong with the TA2020; it's just a matter of economics.
Will these low-power amps be able to drive my XXXX speakers with 8X-dB sensitivity?
- Many have good results even with as low as 86 dB/m. Room size, preferred listening levels, etc. all count. And keep in mind the clipping issue. These amps don't overload gracefully, so you'll have to operate them leaving enough headroom to avoid clipping or even overheating. The Tripath chips have good fault (temp, load, etc.) sensing, though not all amp designs take full advantage.
Which amplifiers require break in?
- Charlize, SI T-Amp ... Many have reported that their Tripath-based amps sound better after extended run-in. Amps with more and larger capacitors take longer to break in. Virtue recommends 100 hours, for instance.
Charlize Specific
General Information
What are the dimensions of the Charlize?
- 3 x 2 x 1 inches for Width, Length, Height
What is the gain for the Charlize Amplifier?
- Gain is 12 dB if ratio of input resistors is 1:1.
How do I remove the start-up "pop" when turning on the Charlize?
- This involves using a rotary switch and a resistor to create a "soft start" circuit.
- See near the bottom of the [Charlize webpage].
- You can also make a simple circuit to do this automatically [2]
- It'll be removed by adjusting offsets and relay circuit. Refer [DIY Digital Amp --TA2020-20--]
When I turn up the volume, the sound drops out then comes back on? What gives?
- This issue usually occurs with 2- or 3-way speakers because the crossover circuit and speakers are more reactive than a single driver and thus create a more difficult load on the amplifier. An ideal load would be purely resistive, but we all know that isn't the case with any of the current loudspeaker drivers. You need a better behaved crossover/driver combination, or a full-range driver with no crossover, or more efficient drivers, or a larger power amp design, or one amp per driver and an electronic crossover (bi-amp or tri-amp), or each of these.
- Or turn down the volume, to fix the problem.
Modifications
Air Core Inductors
Input Capacitors
- Charlize normally comes with Cerefine input caps. They are the two red caps right next to the input solder pads.
- If you replace the Cerefine with Blackgate N, I think you will notice an improvement. If you're adventurous, however, you may want to try some of the premium film caps, like Mundorf, Dynamicap, Auricap, Jupiter, AudioNote? copper, V-Caps, teflons, etc. These may potentially be an even better upgrade, though each of these is more expensive than the Blackgate N's and will involve finding a way to secure the caps to the chassis and routing the leads to the holes. You may want to try a lower value, like 2.0 to 3.0uF, as film caps become prohibitively large and expensive in the larger values.
- If you want to really learn how these caps sound compared to the Cerefine, build your amp with the stock Cerefines and listen for a few months. Then make the change and see what changes or improves.
- Installation tip: Take note of where the negative legs of the Cerefines are oriented. Normally with a polarized electrolytic cap, the negative leg will face the lower voltage potential and the positive leg will face the higher voltage potential - normally the negative leg facing the circuit downstream and the positive leg facing the input signal.
- You'll notice that the polarity orientation is reversed in the Charlize, however (with "-" facing the input signal). That's because the Tripath TA2020 chip operates with a positive biasing voltage on the circuit. That makes the voltage potential on the circuit board greater than that of the input signal. Therefore, in the Charlize the positive leg faces the circuit board and the negative leg of the cap faces the input signal.
- The Blackgate N's are non-polar, however, which means they will operate in either direction and are not marked with a "-" leg indicator. The Blackgate N's do have a long leg and a short leg, however, which indicates which leg attaches to the inner foil and which one attaches to the outer foil of the cap.
- Several folks on the forums, notably Peter Daniel, have experimented with the orientation of the BG-N's foil to see which orientation sounds more favorable. I have not tested this myself in the Charlize, but I took Peter's findings as a starting point.
- He found that in a conventional circuit, the BG-N's sound better with the shorter leg facing the input signal (higher potential). Since the higher potential in the Charlize is on the the circuit board, however, I oriented the BG-N's with the shorter leg facing the board and the longer leg facing the input signal.
- You may want to experiment with this as I'm not sure which way actually sounds better in this circuit.
- Keep in mind that the 10uF 50V BG-N's are wider than the Cerefine's, so you'll want to keep the plastic on the caps to prevent the left and right input signals from shorting together if the caps touch each other. Also, if you use 10uF 50V BG-N's, you might have to leave the leads a little bit longer so that the caps hover above the board slightly. Then you'll have to bend the caps away from each other at the top to create clearance at the bottom so they don't touch each other. The final configuration will look like a V, with the top of the caps further than the bottoms, but you'll need to do this in order to keep them from touching.
- Alternately, you could use a smaller value BG-N, like 4.7uF 50V, which should be about the same physical size as the Cerefine. You'll be able to press these flush to the circuit board without fear of the caps short-circuiting against one another. You could experiment with taking the skins of the caps, if you desire, to see if this improves the sonics.
Sources
Recommendations by 32bit user
A list of recommended modification parts, brief explanation of the expected "improvement", and some suggested sources (with part numbers, typical pricing, web addresses, and/or phone numbers). Perhaps the sources could be broken down by major geographic location. And, of course, the parts would be broken down by specific item being modded.
More power from your TA2020 series, by Alastair E
It is possible to parallel the outputs of a TA2020 and its bridged O/P S.M. friends, but careful attention must be paid to the output voltage offset of each channel. A simple dual-opamp servo-circuit was documented by Tripath some years ago, when the TA2020 first came out. It was envisaged that a bridged-output TA2020 would be used for subwoofer duties at impedances less than 2.5 ohms. In this configuration an output power of 50W was possible.
Through many experiments with the TA2020, it was found that it will quite happily drive a 2-ohm load without resorting to parallelling its outputs, provided that O/P voltage overshoot was taken into consideration. Output overshoot above the supply rails can otherwise destroy the device. Most recent production boards contain the extra diodes needed to protect the TA2020 and its friends, but care must be taken to check older evaluation boards such as the TA2020-EB.
Extra decoupling caps of 470uF-1000uF, mounted directly across the power supply pins at the chip, are also recommended. Low-ESR types should be used.
It is worth mentioning that at these low impedances and high-output power a heatsink is a good idea.
