SUPPLIER Power Supply……Is It Really Worth the Extra Cost?

This is a great question and one we get quite often. Many people just can’t fathom how a power supply can help improve the sound of an audio component. This article applies to all Firestone components that are compatible with the Supplier. (The Supplier is not for use with the Tube Head, Little Country III and Big Joe)

SUPPLIER PSU Upgrade
Before we talk specifically about the SUPPLIER Power Supply Upgrade lets talk a little about power supplies in general. If you look at the history of Hi-Fi one can see the continued progression of bigger, better and cleaner power supplies being added to high-end components. If you examine any high-end component you’ll find that clearly half the cost or more is in the power supply section. One could argue that improvements in electricity are the source of all improvement in Audio.

If you could order up the ideal power supply it would be one that provides unlimited current while the voltage remains perfectly constant. Nice in theory but not practical in the real world as every type of power supply has limitations that stray from this ideal. As with most any audio component, the Firestone products use DC voltage to power their circuits. They require a clean, stable 24 volts DC to sound their best.

Lets look at the three types of power supplies commonly used in audio

Batteries
Either “one time use” or rechargeable

Batteries, especially the rechargeable type, are pretty much an ideal power source for audio components if they are correctly sized. A battery is a reliable source of clean, quiet power. That is if the battery is large enough to power the component for a reasonable time without significant discharge. One problem is that the impedance of a battery increases as it discharges, the higher the impedance the faster the rise in voltage ripple. If the frequency of the voltage ripple is in the audio range then this can cause undesirable noise to be heard from the component.

Another obvious con for battery powered systems is the constant requirement for either replacement or recharging.

Wall Wart power supplies
This is the little black box supplied with your Firestone Audio Component (FAC)

The standard wall wart power supply is a non linear, unregulated power supply; these are the simplest and least expensive solution for powering your Firestone product.

With the wall wart you have 120VAC going in and 24VDC coming out (assuming a stable 120VAC source). It includes a rectifier to convert the AC power to DC and a smoothing circuit to help tame the pulsating DC. Unfortunately there is still a significant amount of ripple on the DC side and the small space available in most wall warts limits the amount of filtering that can be used to reduce the ripple. The result is degradation in the DC power and a corresponding degradation in audio quality.

Another problem with an unregulated power supply is that the output voltage will rise and fall with changes to the input voltage. Any variation on the AC input side will be directly translated into DC variation on the output side. If your AC wall power has hash, surges, spikes, brown outs or some other ugliness; this will appear on the DC side as well and degrade the audio quality. These DC artifacts are known as noise and ripple. Fortunately your FAC is equipped with ”power regulation” and “low pass filter” circuits to help minimize the bad effects of this.

Last but not least is the low power output capability of the wall wart. Electronics that are “power challenged” tend to sound thin or flat at frequency extremes and don’t have the oomph to follow the peaks and large dynamic swings in the music. The FAC’s as with any audio component will draw considerably more current during intense passages in the music; this is when the wall wart may not have the jam to follow along.

Linear, Regulated Power Supplies
This is the SUPPLIER Power Supply upgrade.

To help deal with the AC voltage variation and other assorted nastiness from the wall power, the Firestone engineers designed the SUPPLIER power supply. The SUPPLIER is a linear, regulated power supply so this means the DC output voltage is largely independent of the AC input voltage. It is designed to output a stable 24 VDC despite variances to the AC input voltage. Is it perfect? Of course not, but it’s a major improvement over the relatively large voltage swings seen at the DC output of a wall wart.

The Supplier also has vastly superior filtering for both DC ripple and noise. This is where you’ll experience a majority of the increase in sound quality; tighter bass, clearer highs and a better defined midrange. To my ear the biggest improvement is in the dynamic contrasts, dynamics are noticeably improved. Also, if your system can reveal it you’ll experience an increase in the magical, low level detail as the line noise and hash present with the wall wart are filtered away by the Supplier.

The SUPPLIER also has much higher power output and superior reserve power compared to the wall wart. Its high current output effortlessly follows the music regardless of dynamics and helps your FAC deliver the very best from the music.

So is it really worth the extra cost?
YES, with one exception. If you are using the Fubar II with a low resolution system then the improvements may not be as apparent. I personally can detect the addition of the Supplier 100% of the time in my system in an A - B - A test; all I have to do is listen to the low level detail in the music

The Supplier is highly recommended for the Spitfire, Cute Beyond and Fubars!

 Want more? Here is a great professional review on the Supplier Power Supply.

Enjoy!

The Fubar II and Fubar III USB DAC’s have a few different operating modes you’ll see once they are powered ON. You can tell what mode the unit is in by observing the indicator lights.

But first off, lets define the lights on each unit and cover off a few distinctions between the Fubar II and III.

The Fubar II has three lights: Power (blue), Suspend (red) and Playback (green).

The Fubar III has only two lights; Power (blue) and a Combination Suspend (red) / Playback (green)

Here are the different modes you’ll observe while using the Fubars

Mode 1
The PLAYBACK light is ON: This indicates there is a signal from the computer and information is being transferred. (eg. you’re playing a song) this is my favorite mode by far!

Mode 2
The SUSPEND light is ON: This indicates there is no connection detected from your computer. The Suspend light will come on when your computer goes to sleep. The light also comes on if the USB cable comes disconnected when the unit is powered on.

Mode 3
Both the SUSPEND and PLAYBACK lights are OFF:  This indicates a good connection to the computer but no information is being transferred. You may occasionally see the playback light “flash” as a computer sound or other bit of information is sent to the Fubar. You’ll also hear the same sound from your speakers if your amplifier is turned on.

Hope this helps clear up any mystery surrounding the Fubars and their indicator lights

As always we welcome your Comments, Questions and Feedback

Firestone Audio
Series or Shunt Setting for the Volume Control, , Which is Better?

All of the Firestone Audio components with a Volume Control offer you a choice of two settings - Series (default) and shunt modes. Switching between series and shunt changes how the circuit “sees” the volume control and potentially changes the sound.

Here’s a diagram showing circuit differences.  shunt / series diagram

In the series position the volume control is in series with the audio circuit, so the audio signal goes through the volume control and then to the amplifier. This is the default setting for all Firestone products.

In the shunt position the volume control is in parallel with the circuit, so the audio signal goes directly to the amplifier and doesn’t pass through the volume control. The volume control in this instance works as a shunt.
 
One position is not necessarily better than the other and there’s really no reason to change the setting if you are happy with the sound. But if you are an insatiable tweaker like me and just can’t leave things alone or are just plain curious then it can be fun to experiment with the settings.

An improvement can be heard by some people using one setting or the other so you may find you develop a preference as well.

Changing the setting does not turn off or defeat the volume control it only changes how the circuit “sees” it.

If you want to evaluate the two positions then I suggest trying one position for about a week or so and getting a really good feel for the sound. Then switch and try the other position for about a week and then switch back again. That should tell you if you have a preference for one over the other.

If you are using a separate preamp to adjust volume and are not using the volume control on the component then most listeners find the best sound using the shunt position and the 12 o’clock setting on the volume control.

Here’s the procedure for changing the setting.

1. Remove the 4 top cover screws (2 on either end) using the little Allen key supplied with your unit. Then remove the top cover.
2. Once the top cover is off you’ll see the dip switches located beside the volume control.
3. Move both switches to “ON” for the shunt position. Moving both switches to the “1-2″ position is series.
4. When you complete the adjustment, replace the top cover and reinstall the screws. Start all 4 screws for a couple of turns and take care to get them started straight to avoid cross threading and then lightly tighten.

That’s it; the entire process takes less than five minutes. Please let us know how you make out and if you prefer the series or shunt setting. As always, we welcome your questions, comments and feedback. 

To view the complete Firestone Audio lineup visit us a AudiophileProducts.com

I received the following question this morning so I thought I would share the answer as my first blog post.

Q. Hi Todd, Thanks for letting me know about the release of the Little Country III, So far I’ve been hearing good things about it. How does it compare with the Little Country 2 ? What are the main differences?
Dave

A. Hi Dave,

It’s nice to hear from you, thanks for your inquiry.

As you know, prior to the LC3 the Little Country 2 was the flagship product of the Firestone Audio lineup. It combined a hi-end tube headphone amp and preamp in an attractive package that sounded great. Reviewers and owners alike raved about the Little Country 2 and with good reason, the sound quality was outstanding and it was a great value.

But the Little Country 2 was not without its gremlins. The dreadful S type “power transfer cable” would come loose and cause a myriad of problems; this was compounded by the power switch being located right beside it on the back panel. The stock Electro Harmonix tubes were “bass fat” and muddy, (admittedly the tube thing was an easy fix). There was also the internal gain switch that turned a 5 second task into a five minute one. The LC2 also had some issues with “current rush” to the tubes at startup and had little protection for headphones and speakers.

So what has Firestone Audio done to address these issues?

First of all, the Little Country was off the market for over a year. The Firestone engineers performed a complete and major redesign and addressed all of the issues above and more!

1. The Power Supply unit is now in a separate module and connects to the main unit with a high grade cable with threaded connectors. No more S type cable. Yeah!

2. They’ve added a brand new power regulation module that has a built in “soft start” circuit to protect the tubes and also added speaker and headphone protection circuits. This new Power regulation module is also responsible for a high degree of power conditioning which adds tremendously to the sound quality.

3. The tubes have been changed to 2 x 6922. The 6922’s remain pretty much the defacto standard for preamps. Yes the LC3 still comes standard with Electro Harmonix tubes but I enjoyed listening to it for over two months with the EH tubes and only recently switched to Telefunken. The point is the 6922EH are not horrible but there is room for improvement here in my opinion and there are loads of different 6922 and derivatives to choose from on the NOS market.

4. The LC3 now has an external gain switch as it should.

These are some of the more notable changes and upgrades. All in all I would say that Firestone has done an outstanding job of improving on what was an already excellent product and I highly recommend the LC3 to anyone looking for a hi-end tube headphone amp. And it costs less now too!

Find out more on the new LC3 headphone amp / preamp by visiting the Little Country III page.

We welcome your questions, comments and feedback