CCY Engineering F7 Power Amp Part 1 - An Introduction

Here we have another hifi product designed and made in Malaysia, this time it is a power amplifier. 

What excites me about this amplifier is its design. Its topology, as I understand from Mr. Chong the head honcho of CCY Engineering, borrows heavily from Nelson Pass' design in his First Watt F7 model. I am a big Pass Labs fan since its Aleph days (I still have an Aleph 3 power amp in my collection) and am a very happy user of a pair of XA160.5 monoblocks. However, we don't come across First Watt much, if at all, in Malaysia, as it doesn't have a local distributor/dealer, but I have long desired to listen to a First Watt amplifier. 

So, when I heard that CCY was making a power amplifier based on a First Watt design, my interest was piqued. A friend bought one of the early CCY F7 units coming out of CCY Engineering. He allowed me to hijack it for a while to do this series of write-up/reviews (Lim, thanks!). The unit was duly delivered to my place by Mr. Chong himself a few days ago. In this first write-up I would like to touch on its design and I'll cover its sound performance in the next few articles. 

As far as I could ascertain, the CCY F7 amplifier is the second amplifier coming out of CCY Engineering. This second amp continues with the creative, unique, idiosyncratic and almost whimsical chassis design of the first amplifier (the CCY A2450), with the colour of faceplate changed from red on the previous model to black. 

From the photo you can see that the amplifier, uniquely, uses an I-beam as its main body, giving it an elongated, slightly-longer-than-a-shoe-box shape. The circuit board is attached to the underside of the central plate of the I-beam, with the metal plate itself acting pretty much as a heat sink, which is an important necessity as the CCY F7 is a Class A amp.  

The back of the amp is pretty straightforward, it has a IEC power inlet, a pair of RCA input, and a pair of loudspeaker output which, not very conveniently for me, takes only banana plugs as I'd prefer spade which offers a tighter and more secured contact for amp and loudspeaker, I feel.

You would also notice that the amp does not come with a power on/off switch. This is not much of an issue if you can switch the amp on or off at the wall. But if you can't, e.g., if the amp is plugged into a power conditioner that is shared with other equipment, CCY includes with the F7 an umbilical cord with a massive power switch, which your powercord can then plug into. 

First Watt amplifiers are pretty much niche products, they produce low output power (less than 25 watts into 8 ohms), but have relatively high power consumption and run hot, as they are Class A amplifiers. The CCY F7 is no exception to this Class A mould. While First Watt has not published the F7 schematics officially, as it is still one of the current models in its lineup, Chong has based his F7 version on information and high resolution photos and images of the First Watt F7 on the internet.

Chong told me the following about the CCY F7 amp, I quote:

"Topology highlights -

1. This is a push-pull class A amp, running on negative feedback, the uniqueness is that it also applies some amount of positive current feedback from the output captured right AFTER the speaker load back to the input.

As speaker impedance changes across the music bandwidth, the lower the impedance goes, the higher the positive feedback sent back and superimposed with the input, here’s the magic of the F7.

 Build highlights:

1. Dual Mono setup, left and right channels are electrically isolated.

2. All-in-one PCB Layout, no flying wires on any connector other than the transformer.

3. Input stage with NOS Toshiba JFETs 2SJ74/2SK170

4. Output stage with Exicon Lateral Mosfets ECX10N20/ECX10P20

5. O-shape Toroid Transformer

6. DC offset Relay speaker Protection.

7. A total of 144,000uF(72,000uF/channel) capacitance with CRC configuration at Power supply.

 Specifications:

1. 20W @ 8ohm / 30w @ 4ohm

2. Gain 14dB

3. Input Impedance @ ~25k ohm

4. Output Impedance @ ~0.4 ohm"

The underbelly of the CCY F7 is protected with a wire mesh, the circuit is visible through it. Better photos of the innards can be seen on CCY Engineering's facebook page https://web.facebook.com/CcyEngineering-109995560498110. Here is a photo I found on the FB page, with the big O-shape toroidal transformer seen to the front of the amp:

My immediate task now is to run it for a short while, as it is new out of the box, then do some serious listening. I'll do my listening sessions with some speakers that are commensurate with the CCY F7's price point and will also throw something more challenging at it to see how it will fare. 

I'll share some background of CCY Engineering's founder Mr Chong, together with my listening impression of the amp in my next few write-ups. Stay tuned.