I'm actually using 2a3/6C4C outputs rather than 300b, but since this thread is about driver tubes I thought I'd mention the E80CC which I'm listening to now. It's resistor loaded and running at 160v a-k, 5mA, -2v. I had hopes for this tube, since it's often described as better than all the 12A**7 options and a few other besides. In my smallish room the volume was OK though nothing to spare.
I tried out a Mullard made in Holland with gold pins, so I assume rebranded Philips. I found it disappointing - voices were rather flat and a bit boxy. There is a Tungsram version which gets better reviews. I don't have any of those but I may look into it. I haven't seen the E80CC mentioned as a driver tube so I thought I'd try it out. The ECC40 is a similar possible tube, since it was the immediate predecessor of the E80CC. I don't know if anyone else has tried these tubes?
I tried out a Mullard made in Holland with gold pins, so I assume rebranded Philips. I found it disappointing - voices were rather flat and a bit boxy. There is a Tungsram version which gets better reviews. I don't have any of those but I may look into it. I haven't seen the E80CC mentioned as a driver tube so I thought I'd try it out. The ECC40 is a similar possible tube, since it was the immediate predecessor of the E80CC. I don't know if anyone else has tried these tubes?
E80CC has enough gain (if you use it with high AC impedance -CCS, gyrator- load) to produce 160-170Vpp output.
As a driver for el84 triode SE I tried both E80CC (philips pinched waist) and ECC40. Found the former boring and the latter great, most notably magical treble. My experience coincides with what you wrote many moons ago: "I think it betters all those tubes like E80CC, 7026, 6N1P etc. It has particularly good treble"
Ah - yes, I did write that. I must try it out. I have a pair of them. I'll see if I can rig something up quickly! It would be a cheap and easy solution if it sounds good.
Right now I'm listening to a E180CC. Sounds pretty good to me with a resistor load. Not perfect, but a viable choice.
Plenty of substitutes as well for this type. Tony Tecson likes it too.
Plenty of substitutes as well for this type. Tony Tecson likes it too.
E180CC can be substituted by 7062, 5965, 12AV7, 6414, 6829. Depending on the operating point chosen it might be possible to use a 12AT7 or a 6211, though I doubt they would sound as good. Never tried those, though. I tried all the others many years ago and have good recollections of them. Not perfect, but still a pretty good sound and a simple solution.
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- Hello, I may have something relevant ---
-- I saw the title of the thread and had to pass along some interesting information , I was just out cruising around a while back and ran into this thread on the Lenco Heaven Forum .
- They are sharing what they are using in their current systems and this gentleman said that - he has built MANY 300B Amplifiers in the past and had recently decided to build a fairly simple 300B Stereo Amplifier for his son for Christmas out of some extra parts he had out in the shed ...
- And he was So AMAZED at HOW GOOD it Sounded that he decided to build himself a pair of 300B Monoblocks using the Same Design and then said that it was Much better than any 300B he had built in the Past -- !!!!!!!!
( the fellows name is Martin , his Username is low pitch )
---------
Here is the Quote from the thread --
" Power amps below, SE 300B with choke loaded c3g driver run off the cathode - the Full Monkey . I built many 300B drivers but this circuit really stands out. I think it must be the local feedback you get from the common cathode string. I built an amp for my son for Christmas from shed junk and it was the best thing I had ever done. So I made a pair of mono blocks for myself. It's a really simple build, great for diy. TentLab filament supplies. There is a 6AX4 tube diode on the power transformer centre tap for slow warm up. (500-0-500V CLCLC)"
------------------------
- If you are interested here is the Link to the Thread --
- https://www.lencoheaven.net/forum/index.php?topic=25680.0
Here is the 300B Amplifier Schematic he posted --
here is the Monoblock he built for himself -
And here is the double deck Stereo version of the Amplifier he built for his son for Christmas -
----------
For fun here is his system -
- Hope this is helpful for someone , I am thinking of maybe building a pair in the future -
Thanks,
Kind regards, Dean
- Hello, I may have something relevant ---
-- I saw the title of the thread and had to pass along some interesting information , I was just out cruising around a while back and ran into this thread on the Lenco Heaven Forum .
- They are sharing what they are using in their current systems and this gentleman said that - he has built MANY 300B Amplifiers in the past and had recently decided to build a fairly simple 300B Stereo Amplifier for his son for Christmas out of some extra parts he had out in the shed ...
- And he was So AMAZED at HOW GOOD it Sounded that he decided to build himself a pair of 300B Monoblocks using the Same Design and then said that it was Much better than any 300B he had built in the Past -- !!!!!!!!
( the fellows name is Martin , his Username is low pitch )
---------
Here is the Quote from the thread --
" Power amps below, SE 300B with choke loaded c3g driver run off the cathode - the Full Monkey . I built many 300B drivers but this circuit really stands out. I think it must be the local feedback you get from the common cathode string. I built an amp for my son for Christmas from shed junk and it was the best thing I had ever done. So I made a pair of mono blocks for myself. It's a really simple build, great for diy. TentLab filament supplies. There is a 6AX4 tube diode on the power transformer centre tap for slow warm up. (500-0-500V CLCLC)"
------------------------
- If you are interested here is the Link to the Thread --
- https://www.lencoheaven.net/forum/index.php?topic=25680.0
Here is the 300B Amplifier Schematic he posted --
here is the Monoblock he built for himself -
And here is the double deck Stereo version of the Amplifier he built for his son for Christmas -
----------
For fun here is his system -
- Hope this is helpful for someone , I am thinking of maybe building a pair in the future -
Thanks,
Kind regards, Dean
Attachments
Hi Dean/hallcon3,
!Out of the Blue...Very refreshing to see this!
Martin's design was first presented on the Joelist back in early January, 2016. Thorsten had some suggestions for caps to be added to Martin's original design which were incorporated. The design point for which came out of the WE 300A/300B tables of design points as Va-k 350V, Ia 50mA, 5K load, one of the lowest distortion entries in the table and Martin's rationale for picking it. Never mind there are other perhaps more captivating design points, not in the tables, but in the curves presented.
Martin's 200H/2330R chokes came from a now defunct ebay offer, and I went for a pair and still have them...but mine are more like 2550R.
None the less,
!Out of the Blue...Very refreshing to see this!
Martin's design was first presented on the Joelist back in early January, 2016. Thorsten had some suggestions for caps to be added to Martin's original design which were incorporated. The design point for which came out of the WE 300A/300B tables of design points as Va-k 350V, Ia 50mA, 5K load, one of the lowest distortion entries in the table and Martin's rationale for picking it. Never mind there are other perhaps more captivating design points, not in the tables, but in the curves presented.
Martin's 200H/2330R chokes came from a now defunct ebay offer, and I went for a pair and still have them...but mine are more like 2550R.
None the less,
None the less, ...
Good to see Martin's 300B Monkey show up here as it's been one I've been contemplating building for some time. But I'm thinking of higher primary impedance OTs.
Further, Martin is Martin Seddon, proprieter and builder of Azura Horns, axisymetric horns built to John Michel Le'Cleach's developments. You can Google his website and find it
Good to see Martin's 300B Monkey show up here as it's been one I've been contemplating building for some time. But I'm thinking of higher primary impedance OTs.
Further, Martin is Martin Seddon, proprieter and builder of Azura Horns, axisymetric horns built to John Michel Le'Cleach's developments. You can Google his website and find it
Hi,
In the Lencoheaven blog, Martin added "I got the Hasimoto H20-14U a few years back for a 211 or 845 amp project I never started. They are 10K / 14K Ohm, but I use them as 5K loads for the 300Bs, which trades off some power for more inductance and linearity, good for bass phase rotation." With impedance ratio being equal to turns ratio squared, I expect he accomplished that by (for example) connecting an 8 ohm loudspeaker to the 10K:16 ohm terminals, which would reflect an 8 ohm secondary load to the primary as 5Kohm.
Best, RC
yep we know not the best bandwithd on 10/14k and not so induttance too on japan iron , I use 5k on 300bxls btw....
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Hi,
Yep, yep, but It's the bricoleur approach...use what you've got...how many amps do you have with that approach? It's better to have one than zero.
Cheero, RC
300B Operating Points
Hi,
For anyone interested in the possibility of lower power, lower distortion 300B operating points, I am attaching a table of operating points for 6K and 7K output transformers derived from the curves presented in the original 300A/300B data sheet.
Best, Robert
Hi,
For anyone interested in the possibility of lower power, lower distortion 300B operating points, I am attaching a table of operating points for 6K and 7K output transformers derived from the curves presented in the original 300A/300B data sheet.
Best, Robert
Attachments
Thanks. I prefer 5K for a 300b and in fact one of the best sounds has been with the LL1682/50mA which is 5K into 5 ohms. Much better to my ears than with the LL1664/70mA (3K into 8R) which I also have and which is better with a 2a3.
- Hi Robert , Question from a newbie - " It's the bricoleur approach "
- Not sure what you are referring to, could you explain please?
Thanks , Dean -
It's French. A "bricoleur" is a DIY kind of person who finds workable solutions in what he has available. From the verb "bricoler", to potter about, do odd jobs, knock together something that works. Nice word, like many French expressions which exactly fit.
Hi,
Andy has pretty much nailed the definition. I would just add again that It requires a mindset that asks "How can I do dat with what I've got?". In Martin's case, he employed output transformers that had been sourced a long time ago for a different, never started project. And for his monobloc pair he repurposed a pair of chassis that he had, and doubtless some other components from his "shed". If you haven't been to architecture school, you might never have encountered bricoleur...that's where I learned it. But, this a good place to learn it too!
Best,
Robert