All about electronic valves and hi-fi
I’ve got asked the question on how an EML20 (or EML30) can drive an EML45B. Answer is straight forward and hopefully this brief blog entry can shed some light to this request.
I recently looked back again on the EML20A. With a gain of 20, it’s a good candidate but it hasn’t got just enough gain to drive the output stage to full power:
If you have a small room and high-efficiency speakers, then keep reading. If not, you can still enjoy reading about probably the best sounding output valve in my view. The 45. I wrote about it few times and have to say, it’s still one of the best. Better than a 300B but unfortunately can do only 2W. You can use it in Push-Pull and is superb. Have a look at this.
This design is inspired on the great work from Gary Pimm. The 47 is a sterling directly heated pentode and worth using it. I have several on my stash, including some good globe versions.
A belated test of this simple, yet effective PCB. I made it as small as possible, however in order to provide flexible connections, it’s actually double the size. Still at 4 x 4 cm is small enough.
Back at the beginning of the year I purchased a pair of Emission Labs 300B for my new amplifier version (still working on it). I own several 300Bs but was keen to try these out given their reputation.
Jac from JacMusic sent me a matched pair which I traced them with the eTracer:
Pentode drivers are very interesting. You can get excellent results out of them. Here is my version of a differential pair using pentodes. I want to try them out in the 45 PP design I wrote previously Continue reading “Pentode Differential Pair (Hybrid Mu-follower)”
The 45 DHT is probably one of the best sounding valves out there. In fact, I have struggled to get a similar level of detail and timbre in a 300B or 4P1L output stage. Even my 814 SE Amplifier (which was class A2 and had thoriated-tungsten filaments) couldn’t replicate that sound. I posted time ago my incarnation of the 45 single-ended amplifier here. The main challenge with this valve is that it can only put out there nearly 2W, not more. With its 10W anode dissipation, you will struggle to get more juice from it in class A at a low distortion level.
However, if we look at a push-pull amplifier with the 45, we can hopefully retain the timbre characteristic of the valve, despite it won’t be a single-ended one. Well, I love good PP amps, so why not?
Long time ago I used this SLCF circuit as an output buffer with excellent results. It sounds as clean as it can get in my opinion. Recently, I made up a PCB to hold this circuit with a varied of options:
The new listening room (at least for some time) is now ready. One of the loft rooms is now purposed for guests and for music. Everything is set up. The 4P1L PSE with Monolith Magnetics S9 OPTs, the ER801a driver plus the 01a preamp are in place. Have the DAC and the Lenco turntable as sources. A Kozmo stepped attenuator and input selector. Subwoofer, record cleaning machine and the Alpair 10 in the reflex boxes. I removed the dome tweeters to experiment for a while.
My Starlight transport and discrete DAC are on the box still. I need to fit the CD towers on the wall first. Tons of CDs to rack again. Yet, TIDAL is a good alternative. Love exploring other records I don’t own.
At the moment playing the Howling Wolf record we enjoyed late at night with Jeffrey Jackson and Dave Slagle at ETF.18.
Life is good….
It’s been far too long since I last posted on this blog. With the limited spare time I’ve got these days, I concentrated in setting up the new workshop and system since we moved back to our place. I’m nearly there, so now it’s time to get back to work
I made some updates to the “gyrator” PCB. I’ll stop referencing it gyrator from now on, since the name is misleading. However, it got popular that way. Nevertheless, it’s a hybrid mu-follower circuit but if only if you take the output from the anode, it behaves like a “gyrator” from a frequency response perspective. If you’re interested in this circuit in more detail, please read the lecture I gave last year at ETF.18. You can download it from here.
Back to the board, here are the few changes made:
Continue reading “Hybrid Mu-follower (aka Gyrator) Rev08 PCB Update”
