How to connect an amplifier to a receiver without pre-outs/RCA connectors (2023)

Despite what you may have read elsewhere,It's not impossiblefor connecting an amplifier to a receiver without pre-outs or additional RCA connectors.

I'll show you what you need to know with my clear and detailed diagrams, examples and lots of useful information.

Read on to find out more!

First, some basics about receivers, cables, and audio signals

In this article, I will address the following home stereo receiver challenges:

• No RCA connectors (phono preamp)
• Receiver with digital audio only or available HDMI output jacks

Here we will cover a few things first as I have noticed that some information is incorrect. I want to make sure you get the best information.

Common cable types

The cables you need depend on the available outputs on your receiver.There is no standard set of audio output jacks for receivers, so it could be none or more of the ones mentioned above.

Here is a description of the types of connections we may be dealing with:

• RCA connectors:Also known as preamp output jacks or line level jacks.analogSignal outputs as the audio is not digital and can be directly amplified by an external amplifier.
• Optical digital output:Also known as a TOSLINK connector, this is a digital audio output that will eventually need to be converted back to an analog signal for use with a power amplifier. You can connect an optical cable to connect to receivers with this type of input. Signals are transported with pulses of light rather than electrical bits.
• Coaxial digital output:It uses an RCA connector that connects to an RCA cable to carry the digital audio with electrical bits.Note that you cannot connect it to the phono input jacks of a stereo amplifier.– it must be converted back into an analogue signal.
• HDMI output:This is a format that uses a multi-conductor cable to carry digitally encoded audio and video data. HDMI connections on a home theater receiver typically require you to connect the input to a TV or the HDMI output to a set-top box. The receiver can then provide an output for use with other devices.

The audio connections listed here are fairly typical and always depend on the specific model. Some compact home theater receivers have a built-in amplifier and will also decode surround sound formats, providing multi-speaker outputs but no RCA jack outputs.

Digital audio outputs explained

Digital outputs, as mentioned above, transmit sound in a digital format made up of bits of information. A standard home stereo amp can't convert a digital input (unless it has a built in function) so you'll need a digital to analog (RCA) converter box to do the job and provide output jacks to connect to can your amp.

**Note: An integrated amplifier with digital audio input can be connected directly in some cases, although this is not very common.

I won't go into the preamp output or using the auxiliary output (here's why)

I've noticed a few other articles on the web on the subject that mention using other types of jacks on an older receiver or receiver without pre-outs.How does that make sense?

If you're here, it's probably because you don't have anything to use, or one of these other issues:

• They only work in certain modes of the receiver's audio settings (like TAPE, EQ, etc.) and not for FM tuner or other functions.
• They have an awfully weak signal output (like some old receivers) that you can't get enough volume with.
• Other issues not mentioned above.

In some cases, you might even have a receiver with a subwoofer output. However, a subwoofer output (LFE connection) is useless if you want full-fledged sound from your external amplifier as it only provides bass frequencies.

DIAGRAM AND EXAMPLES - Connecting an amplifier to a receiver without pre-outs

1. Connecting an amplifier to a receiver with only speaker outputs

For receivers that don't have other options available, using a speaker level adapter is a great way to connect your receiver to a power amplifier. A line level converter is connected to the speakers using the speaker level input cable provided.

To use one, simply plug it in in one of two ways.

• In addition to the existing speakers that are already in use (in parallel with the stereo speakers that you are already using).
• To unused speaker outputs.

Just connect it according to the provided speaker wire polarity and you're good to go!

The receiver's speaker outputs are reduced to a low-level signal (phono pre-out, phono pre-out, line-level, etc.) that your amplifier is safe to use. They are quite cheap, only costing around $15-$25 for good quality. Some also have adjustable output volume control features that allow you to adjust the input level of your amplifier needed for the best, distortion-free sound level.

I strongly advise against buying the cheapest you can find as not all are created equal. For the best stereo sound, you need a well-designed device. Below I explain more about how they work, the sound quality and the speaker ohms the receiver will see.

2. Connecting an amplifier to a receiver with digital outputs

Digital-to-analog converters process digital audio and convert it to standard stereo outputs. They offer RCA jack outputs in some cases, or a 3.5mm jack (1/8″ headphone jack).

A digital audio jack gives you very good sound quality if you have the option. However, they are not often used because the output is not directly compatible with the RCA inputs of a stereo amplifier. You need a digital to RCA converter. They cost around $18-$25 and most include a small AC-DC power adapter.

Most also include the necessary cables to connect to your AV receiver's digital connection, so you can simply use whichever option is available to you: the optical connection (TOSLINK, fiber optic) or the coaxial digital connection.

Note thatFiber optic cables can be damaged if bent too tightly, so care must be taken not to twist or pinch them in tight spaces.This can permanently damage the optical cable material and cause them to fail or have problems transmitting the audio signal.

3. Using an amplifier with a receiver with HDMI output

As I mentioned earlier, HDMI is a format that carries both video and audio. You might think: "How should this be connected to my amp?”

The big news is thisAn HDMI audio extractor can be used to access the digital sound source through an HDMI output and convert it into an audio signal pair that we can use.

To do this, connect an HDMI cable to the input of the extractor and the other end to the HDMI output of the receiver. The audio extraction device extracts the digital audio stream and converts it into analog outputs that you can connect directly to your power amplifier or AV amplifier.

A good audio extractor is only $25 to $50. Note that the HDMI cable is usually separate but only costs a few dollars.

How does a speaker level converter work? Are you all right?

As I have already mentioned, aLine level adapter (speaker level converter) is a type of signal adapter that plugs into speaker terminals and scales the signal voltage to a level safe for amplifier inputs.They provide a way to use RCA wire connections when only speaker wire outputs are available.

How does a speaker level adapter work?

Let's take an example: For an AV receiver with 8 ohm speaker outputs and 50 W power, this means that the output voltage at full power is about:

square_root(50×8) =20 Volt.

However, a stereo amplifier can in many cases only accept an input signal of around 0.5 to 2V - trying to use a much higher voltage with line level inputs will not only introduce distortion, but will also burn out an amplifier's input components .

To avoid this, a line-level converter divides the speakers' input voltage by a factor of about 1/10 (less in some cases) and routes it to the output jacks. Some models also add additional circuitry to support the best possible audio quality or to electrically isolate inputs from outputs.

Will a line level adapter damage my receiver? Are the total ohm values ​​ok?

It's okay to connect a speaker level adapter to the speaker output terminals. The receiver speaker outputs still have a safe speaker impedance (ohm) rating.

This is because they have a very high input impedance (input resistance) and do not extract any real power from the speaker outputs or reduce the speaker's overall ohmic load. This is usually somewhere around 10,000 ohms (10K ohms) or even much more.

The total ohm load your receiver sees doesn't change for it - it's like nothing is connected. It's becauseAn extremely high impedance in parallel with a low impedance has a total ohmic load roughly equal to the ohms of the speaker being used.

Notes on sound quality

The sound quality when using a speaker adapter is generally very good, but not as "clean" as with RCA connections or when using a digital signal and a converter. It also depends on the quality of the AV receiver outputs. Whenever a signal is converted twice, there isalwaysa little deterioration that happens.

In general, though, it sounds good to most people, and unless you have extremely good hearing or audiophile expectations, you'll have a hard time dissatisfying with it.

Can I get surround sound from a receiver without pre-outs?

Usually the answer isNot🇧🇷 However, in certain cases there are three ways to get surround sound from an audio receiver without pre-outs for using multiple speakers:

1. Integrated receivers with surround sound speaker outputs:In receivers of this type, the surround sound decoder and built-in amplifier are built in –You must use line level converters with the speaker outputs.
2. Receiver with digital audio output:You can connect the digital audio jack to a surround sound decoder to provide RCA jacks for front left and right, center, rear left/right, and subwoofer channels that an amplifier can use. You can then line up your surround sound speakers with the correct audio channels you need.
3. Receiver with HDMI output:You can use an HDMI audio extractor with a built-in surround sound decoderORan HDMI extractor and then a decoder connected to your digital audio output.

Unfortunately, if your AV Receiver does not meet any of the 3 cases listed above, there is no other option. This is because surround sound requires at least a 5.1 channel signal to carry a Dolby Digital or DTS audio stream. These can only be transmitted via a digital audio connection (optical TOSLINK, coaxial digital output or HDMI digital audio for 5.1 or 7.1 such as Dolby Atmos).

Receiver with 2-channel cinch outputI cantransmits a decodable signal to Dolby Pro Logic II, since only left and right signals are required. However, if your home stereo receiver doesn't have them, you're out of luck.