Low Cost Single Ended 6CB5A Amplifier - Part 6

Hi!

Many people asked me already how these little monos sound. If you read my article series 'How Does It Sound' you know that I am reluctant to give sound descriptions since they can only be very subjective.

But I understand that there is a lot of interest and that it is difficult to have an idea about the sound from the previous posts. So I will try my best.

The amps have been playing in my small system for over a week now. They have the sound character I am looking for. No harsh sound or annoyance. Neutral frequency response as could be expected from the measurements. Resolution is good.

How do they compare to the transformer coupled version? Of course the bigger version gives more of everything, especially in the resolution department and also richer tone colours. These amps are a stripped down version, so some compromises had to be done.

For the cost of the parts (just below 1000 Euros for all the electronic parts for both monos, without chassis, or about 800,- for a stereo version) I think it gives a more than excellent sound. If you have a good stock of parts yourself and if you are a bit creative with salvaging power transformers or output transformers from old radios, these can even be built for a lot less. The cost mentioned above includes the high quality Lundahl transformer and choke and the excellent quality power transformers.

These amps do not sound 'tubey' at all. They are neutral and have a solid bass given the size of the amps and their power. Of course suitable speakers need to be used with them. Yet they retain the ability of good single ended designs which excel in musical flow.

How do they compare to amps with directly heated triodes? Of course a well implemented DHT amp will give even more of the single ended magic and will be better able to reproduce the atmosphere of  a recording. But to achieve that requires much higher expenses. A poorly designed DHT amp or one with poor quality parts will not be able to compete with these 6CB5As. The system needs to be of very high quality before these amps would become the limiting factor.

As mentioned I have been using these amps for over a week now and I can happily listen to music with them. Even though I have some behemoth amps in the basement, there was no urge to pull one of them over. My last record review was done with these small monos.

Let me share a big secret about how to get good sound with you: Be happy with what you have or rather what you can afford. No matter how much you spent or how much effort you put into an amp, there will always be something better out there somewhere. There are always possibilities to do details better. Stop worrying about sound and enjoy the music! Sounds ridiculous? Especially since I offer much more elaborate and expensive designs myself? I don't think so. I know many audiophiles who are always worrying about the sound quality and are never happy. This is supposed to be fun! Don't do the mistake to listen for the faults in an amp or a system. You will always find faults. Once you concentrate on the weaknesses, that's what you hear. Rather concentrate on the strengths of an amp. And these little buggers have many strengths to offer.

Enough ranting. Here some cool photos which I shot at night:

I hope you enjoyed this series of posts about these amps. If you want to build these or a stereo version of the circuit and need parts, don't hesitate to contact me.

Best regards

Thomas