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Topics - Tranquility Bass

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For more information on this topic please download the following pdf document:-

  How to upload firmware updates to the Ultimate-Preamplifier/url]

For more information on this topic please download the following pdf document:-

How to connect a turntable to the Ultimate-Preamplifier

For more information on this topic please download the following pdf document:-

  Uploading an Audioweaver Design to the Ultimate-Preamplifier

Wiki and Q&A / How to install the 2-channel USB Amanero drivers
« on: March 29, 2021, 12:28:28 AM »
All of our preamps are fitted with an Amanero 2-channel USB interface adaptor. For Mac users there is nothing more to do to communicate with this device. However for PC users they will need to install the relevant drivers to be able to send digital audio to the Preamp.

Please visit the Amanero website to download and install the relevant drivers on your PC by visiting

Test Methodology:

In this test we are looking at how the DAC is good at resolving very low level signal levels or in other words its micro-dynamic resolving capability. In this case we feed each channel a low level digital signal of -90.31 dBFS which corresponds to a full-scale (0dBFS) signal divided by 32768 or a reduction of signal magnitude by 16 bits which is the lowest level for redbook CD ! This is a 32bit DAC so still has plenty of bits left in the tank to resolve this detail ;)


Even with a reduction of level equivalent to 16bits in magnitude we see the Ultimate Preamplier has no problem and resolves it cleanly compared to the DEQX Premate which adds a lot of noise and distortion to the signal.

Performance and Measurements / Ultimate Preamp vs DEQX
« on: March 19, 2021, 10:04:07 AM »

Whilst we don't actually have a DEQX in front of us to test and compare with, we can still leverage the test results from a recent Stereophile review of the DEQX Pre-mate  which apparently is the same hardware used in all of their models with some changes to the I/O and software capability otherwise it is the the same old hardware except for the cheaper models which apparently use a switch mode power supply instead of the linear power supply used in the more expensive models. Of course the UP uses a linear power supply in all of its models ;)

For a detailed comparison between DEQX and the Ultimate-Preamplifier please click here to refer to our comparison table

Test Results:


We can see a pattern emerge here and that in all tests shown below the Ultimate Preamplifier displays superior performance over the DEQX in all cases. Not just a small improvement but a major improvement !

DEQX claim the following from their own website but the measurements from Stereophile review don't really support these claims !

Audiophile-grade engineering

Every aspect of a DEQX is carefully engineered for optimum audiophile performance. For example: countless design, development, and auditioning iterations were put into the latest A/D convertor circuit and the DAC's I/V (current to voltage) convertor circuits. Over a decade of constant refinement and attention to detail has paid off in superlative performance.

Now add in superb digital coding and algorithms: a −140 dB digital processing noise floor and a precision digital volume control. The end result? A truly transparent component with zero digital artifacts. An "analog" sound for all combinations of input to output: analog to analog, digital to digital, and any combination of the two.

DEQX also claim in one of their reviews of "'first do no harm' transparency" but the measurements from Stereophile compared to our own measurements of the Ultimate Preamp show anything but transparency. Add to this an antiquated DSP platform with very limited FIR capability shows that this product is trying to be all things to everyone but succeeding at none of them.

Performance and Measurements / DAC (19kHz + 20kHz) CCIF IMD test
« on: March 17, 2021, 07:21:22 AM »
Test Methodology:

The configuration is loaded with a twin tone in the signal generator, with two high frequency tones (19kHz + 20kHz) at amplitudes of -7dBFS each, and separated in frequency by 1kHz. The analyzer measuring the first-order difference frequency at 1kHz using a highly-selective FFT-based filter.

Test Results:


The following test results show that the IMD distortion of the Ultimate Preamplier is exceedingly low and betters the performance of the DEQX Pre-mate by a long margin !

Performance and Measurements / DAC Filter Impulse Response
« on: March 08, 2021, 12:43:41 PM »
Test Methodology:

In this test we excite the DAC with a 1KHz impulse train at -3dBFS and observe the impulse response on a scope for each of the seven different reconstruction filters available in the DAC settings menu.

Test Results:


Performance and Measurements / DAC - Jitter Tests Part 2
« on: March 09, 2021, 12:48:58 AM »

In this exercise we continue on with the jitter tests using the J-test methodology outlined in our original jitter test thread but this time we want to see how the jitter performance varies as we change the DAC Digital PLL bandwidth. The ES9038PRO DAC has 15 different settings for Digital PLL bandwidth but obviously the tighter the bandwidth the better the jitter performance but this comes at the expense of the DAC being able to lock onto an asynchronous signal with inherent jitter so there is a trade-off between bandwidth and jitter tolerance.

Test Methodology:

There are a variety ways of measuring jitter but the single single RMS or peak jitter metric is not very revealing since it does not reveal the nature of the jitter, so a more detailed analysis such as the J-test method is used to test the susceptibility and tolerance of the device under test. The J-test methodology is described on the ASR forum J-test methodology 1 and J-test methodology 2

Test Results


Below the DPLL BW setting of 5 there doesn't seem to be any more improvement in jitter to be had so it seems like this setting is the best compromise between jitter performance and PLL bandwidth.

Performance and Measurements / DAC Filter Step Response
« on: March 08, 2021, 12:43:41 PM »
Test Methodology:

In this test we excite the DAC with a 1KHz square wave at -3dBFS and observe the step response on a scope for each of the seven different reconstruction filters available in the DAC settings menu.

Test Results:


We had a recent enquiry by someone who wanted us to build a preamp with 16 outputs ! But what if someone asked us to build a 24 or 32 or even a 48 channel or more hi-end stereo pre-amp and our preamp only had 8 outputs? Fear not with the external Link-Port on both the UP2 and UPP you can chain as many preamps together as you need to get as many outputs as you need with no loss of information or performance ! Why would you need such high channel count ? One application comes to mind and that is a phased array loudspeaker or wave shaped loudspeaker with many independent driver channels such as the B&O kii audio etc or even a multiple active speaker that are all controlled by the same pre-amp.

By itself the Ultimate Preamp 2/+ has 8 outputs plus an optional digital output to drive an external stereo DAC bringing the total output count to 10 channels which is still far short of 48 channels. However, the main DSP board used in the preamp has provision for connecting multiple DSP boards as a master and many slave arrangement in the one chassis using the on-board Link-Port connector.

However, from a practical point of view this would require a redesign of the enclosure and power supply to handle multiple boards and output connectors which is just not practical at this point in time. We just needed to extend this facility outside the chassis so that we could link multiple preamps in 8-output clusters and they all needed to sync perfectly together when changing things like the volume, balance, mute etc because you donít want to have to adjust each preampís volume control every time you need to adjust the volume.

Because this was a planned feature for the UP2 and UPP we needed to make sure it worked perfectly before we started shipping the preamps so whilst we still have all of the preamps in our lab undergoing testing before we ship them what better time to test out this feature which is why we have spent the last week updating the firmware and hardware to make sure it all works as advertised. As an example we took 6 preamps and chained them all together in a one-master five-slave system to give a total channel count of 48 channels !. We also loaded the simple Audioweaver pass through example which feeds a stereo signal directly to all 8 channels but this could be any design of your choosing. It also helps us test the HDMI I2S input and the Link-Port HDMI output ports on the preamp at the same time 😉

The bottom preamp is assigned the master preamp and the top five preamps are assigned slave preamps connected in daisy chain fashion using HDMI cables.

These preamps operate in perfect sync with each other and the master preamp controls the volume, balance and muting on all of the other slave preamps in perfect unison.

48 channel VU meter operating in real time !

Muting works across all preamps as well.

A 48 channel Preamp playing vinyl ;)

Performance and Measurements / Clock Fidelity Test
« on: November 19, 2020, 08:02:18 AM »
Test Methodology:

In these tests we are using a wide bandwidth digital scope to view the 49.152MHz master clock waveform at various points in the clock network. It is impossible to make proper measurements of a clock source unless you use a scope with a suitable bandwidth that can at least capture the 21st harmonic of the fundamental frequency of the clock frequency which means a scope with at least a 1GHz bandwidth. Not only that you need to use a probe with an equivalent or greater bandwidth to the scope and preferably an active probe to minimize loading.

To avoid loading down the device under test we use an active probe (Tek P6204) with at least 1GHz bandwidth along with the shortest ground connection to minimize loop inductance in the probe which would manifest itself as ringing in the waveform. We used a Tektronix TDS784A DSO scope with a 1GHz bandwidth and real time sampling rate of 4Gs/s as well as a 10Gs/s equivalent time sampling rate for our measurements. For the expanded scale measurement the scope was set to an equivalent sampling rate of 100 Gs/s. What we are looking for is minimum ringing and overshoot without any kinks in the clock transition interval.

Test Results:


As one can see from the scope shots below that in all cases the clock wave-forms are clean and stable and show minimum overshoot which means that the clock outputs are properly matched to the board traces in order to minimize transmission line effects and reflections.

Tektronix P6204 Low Capacitance Active Probe with 1GHz bandwidth

Active Probe applied to clock circuit using the shortest possible ground connection for minimum induced ringing and overshoot ;)

News Updates / Visiting Purifi Audio
« on: November 01, 2020, 04:34:11 AM »
Since we have an interest in using some of the products from Purifi Audio in a new project this article makes for interesting reading ;)

For more information on this topic please download the following pdf document:-

How to implement a stereo 5-way crossover on the Ultimate Preamplifier

News Updates / UP Extensive Measurements now available !
« on: October 20, 2020, 06:59:36 AM »
The Latest test results and measurements from our Lab show the Ultimate-Preamplifer 2/+ meets or exceeds its design objectives by a huge margin ! Click here to view more.

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