Indeed, this is part of the fun when working with the new FE boards.
I happen to like a little more gain in my system, as my Flat Earther preamp was originally meant to be used with an amp having about 20 dB of gain. I've found that a gain of 7.1 or 17 dB works well as an in-between value for my VFET amp.
The Bulwark boards seem be benefit sonically from having some extra gain:
With the Edcor I set R22 to 2.2k and R21 to 4.75k for an electrical gain of 1.46 and a total gain of 7.3.
With the Jensen transformer, I used 3.32k at R22 and 1.30k at R21 for an electrical gain of 3.55, giving a total gain of 7.1.
In log terms, these are within 0.2 dB of each other, so it's easy to swap boards without having to make adjustments to the volume knob for comparison listening.
Another feature that I like about the Bulwark boards is dual coupling capacitors C2 and C3. I have make different choices for the different transformers. The Edcor version uses a pair of 100 uF Elna Silmic caps. The Jensen version uses a combination of 47 uF Elna Silmic with a 0.33 uF Wima polypropylene.
I happen to like a little more gain in my system, as my Flat Earther preamp was originally meant to be used with an amp having about 20 dB of gain. I've found that a gain of 7.1 or 17 dB works well as an in-between value for my VFET amp.
The Bulwark boards seem be benefit sonically from having some extra gain:
With the Edcor I set R22 to 2.2k and R21 to 4.75k for an electrical gain of 1.46 and a total gain of 7.3.
With the Jensen transformer, I used 3.32k at R22 and 1.30k at R21 for an electrical gain of 3.55, giving a total gain of 7.1.
In log terms, these are within 0.2 dB of each other, so it's easy to swap boards without having to make adjustments to the volume knob for comparison listening.
Another feature that I like about the Bulwark boards is dual coupling capacitors C2 and C3. I have make different choices for the different transformers. The Edcor version uses a pair of 100 uF Elna Silmic caps. The Jensen version uses a combination of 47 uF Elna Silmic with a 0.33 uF Wima polypropylene.
I should know better than to kid around at 11:00 p.m. after a few glasses of Cabernet. The inside joke just seemed funny after the email I received on Monday. Hehe.
I'm delighted to invite everyone to follow the diyAudio Store link below.
Scourge, Bulwark, Marauder, and Dreadnought are now available as full kits including PCB and all electronic components. Yes even the Edcor transformers.
Nelson Pass and member WBS have managed to source all of the necessary components, in the middle of a global electronics supply chain disaster, and provide them to you in the most convenient way possible. They dealt with backorders, sold-outs, unavailables. They identified acceptable substitutions. They bought from whoever had inventory to sell: more than a dozen distributors and brokers. Nelson even dipped into his personal transistor barrels in a couple of cases.
If you're thinking of building one or more of these Front End boards "someday", I suggest that you think hard about buying today while the super convenient kits are still available. After they sell out, the convenience disappears, and then it will be YOU who identifies acceptable substitutions, buys from a dozen distributors, and pays exorbitant shipping fees from Edcor.
If someone wants to look up the date of post #1 in this thread, and then count the number of weeks between the publication of these Gerbers and the availability of kits in the store, I am sure plenty of readers would be grateful for the information. It's the only data we have about how long it can take to get VFET kits into the Store.
Scourge, Bulwark, Marauder, and Dreadnought are now available as full kits including PCB and all electronic components. Yes even the Edcor transformers.
Nelson Pass and member WBS have managed to source all of the necessary components, in the middle of a global electronics supply chain disaster, and provide them to you in the most convenient way possible. They dealt with backorders, sold-outs, unavailables. They identified acceptable substitutions. They bought from whoever had inventory to sell: more than a dozen distributors and brokers. Nelson even dipped into his personal transistor barrels in a couple of cases.
If you're thinking of building one or more of these Front End boards "someday", I suggest that you think hard about buying today while the super convenient kits are still available. After they sell out, the convenience disappears, and then it will be YOU who identifies acceptable substitutions, buys from a dozen distributors, and pays exorbitant shipping fees from Edcor.
If someone wants to look up the date of post #1 in this thread, and then count the number of weeks between the publication of these Gerbers and the availability of kits in the store, I am sure plenty of readers would be grateful for the information. It's the only data we have about how long it can take to get VFET kits into the Store.
Volpar, at the very beginning of this thread I asked a "theoretical" question:
I got one answer and one joke.
That's why I reacted with the "popcorn" image to your question, as I find there is really an aversion in this community to answer such questions.
I cannot afford all versions at this point, so I went with my hunch that Marauder and Dreadnought will probably offer the more 'distinct' sound to the transformer versions.
I too hope there is still stock in the future for the ones I missed, but I have learned the hard way that people here click the "purchase" button faster than I make my decisions and I usually end up wanting something out of stock. So this time around I pulled the trigger as fast as I could with what I could afford.
Let's see!
Thanks MJ and everyone involved in getting these into the store! I certainly understand the level of complexity to source from so many places, so the effort and care for the community is highly appreciated!
Rafa.
I got one answer and one joke.
That's why I reacted with the "popcorn" image to your question, as I find there is really an aversion in this community to answer such questions.
I cannot afford all versions at this point, so I went with my hunch that Marauder and Dreadnought will probably offer the more 'distinct' sound to the transformer versions.
I too hope there is still stock in the future for the ones I missed, but I have learned the hard way that people here click the "purchase" button faster than I make my decisions and I usually end up wanting something out of stock. So this time around I pulled the trigger as fast as I could with what I could afford.
Let's see!
Thanks MJ and everyone involved in getting these into the store! I certainly understand the level of complexity to source from so many places, so the effort and care for the community is highly appreciated!
Rafa.
RafaPolit. My thoughts exactly I too have been paying attention to all the threads. I believe the dreadnought it’s going to be the most interesting so that is my first choice. And secondly the Bulwark. You are right inventory does disappear rather quickly in these current times. I’ve had two very good months of income so like you I jumped on it immediately with a credit card (lol more bills). I’ll be able to pay them off hopefully. But this is becoming the only hobby I’m having interest in. There’s still so much for me to learn. Add for me to be able tinker with these pre-designed sets are these helping me to understand some of the conversations that are going on.
If my memory is correct, there have been two Dreadnought builders who have shared their listening impressions and opinions about its sonics. One of the Dreadnought builds was completely "stock" (exactly following the schematics & parts lists attached to post #1 of this thread) and the other had a relatively large number of parts-swaps; let's call that super-personalized & super-modified.
These builders actually sent the post#1 Dreadnought Gerbers to a PCB fab, bought parts themselves from the Mouser one-click shopping cart, and completed their boards weeks and weeks before the kits became available. Let's call those folks super-motivated. I seem to be saying "super" a lot this morning.
There has also been one Bulwark builder who shared listening impressions and sonics evaluations. Those Bulwark cards were also super-personalized and super-modified.
The reviews written by those builders may not necessarily have been posted in this particular thread. Also check the DIY Sony VFET threads (1 and 2) and the VFET builder's threads. Or just beg them here to identify themselves and provide links.
I don't remember anyone talking about their build of either Marauder or Scourge. Maybe I'm mistaken about that.
Which one do >>I<< recommend? Whichever Front End design appeals to you the most! Want transformerless? Pick Marauder or Dreadnought. Want a Front End that's a voltage controlled current source with a super high output impedance {a "transconductance" amplifier}?? Pick Dreadnought. Want ultra low parts count? Want single ended class-A? Pick Scourge. Want a modern parts reimaginination of Nelson Pass's 1977 preamp design called "Threshold NS10"? Pick Bulwark. Want a Front End card that runs on a 36 volt power supply but swings its output 41 volts peak-to-trough, without a transformer? Pick Dreadnought or Marauder. And oh by the way, moderator 6L6 giggled like a schoolgirl when he saw that the invert/noninvert slide switch on Marauder and Dreadnought, activated a red LED (invert) or a green LED (noninvert) to let you know from across the room, which polarity you've chosen. Maybe THAT might be the deciding factor for you.
Follow your heart.
Want exclusivity? I mean, incredibly rare and impossible to find Front End cards? Locate somebody who qualifies to own the Relentless cards (post #19 of this thread) and barter with them. You may have to "payer par le nez" as the French might say.
These builders actually sent the post#1 Dreadnought Gerbers to a PCB fab, bought parts themselves from the Mouser one-click shopping cart, and completed their boards weeks and weeks before the kits became available. Let's call those folks super-motivated. I seem to be saying "super" a lot this morning.
There has also been one Bulwark builder who shared listening impressions and sonics evaluations. Those Bulwark cards were also super-personalized and super-modified.
The reviews written by those builders may not necessarily have been posted in this particular thread. Also check the DIY Sony VFET threads (1 and 2) and the VFET builder's threads. Or just beg them here to identify themselves and provide links.
I don't remember anyone talking about their build of either Marauder or Scourge. Maybe I'm mistaken about that.
Which one do >>I<< recommend? Whichever Front End design appeals to you the most! Want transformerless? Pick Marauder or Dreadnought. Want a Front End that's a voltage controlled current source with a super high output impedance {a "transconductance" amplifier}?? Pick Dreadnought. Want ultra low parts count? Want single ended class-A? Pick Scourge. Want a modern parts reimaginination of Nelson Pass's 1977 preamp design called "Threshold NS10"? Pick Bulwark. Want a Front End card that runs on a 36 volt power supply but swings its output 41 volts peak-to-trough, without a transformer? Pick Dreadnought or Marauder. And oh by the way, moderator 6L6 giggled like a schoolgirl when he saw that the invert/noninvert slide switch on Marauder and Dreadnought, activated a red LED (invert) or a green LED (noninvert) to let you know from across the room, which polarity you've chosen. Maybe THAT might be the deciding factor for you.
Follow your heart.
Want exclusivity? I mean, incredibly rare and impossible to find Front End cards? Locate somebody who qualifies to own the Relentless cards (post #19 of this thread) and barter with them. You may have to "payer par le nez" as the French might say.
GLOL on "payer par le nez"!!!
Being French, I confess it took me a few seconds to figure out what the hell was meant here... Only to have a great laugh when I got it!
Nice frenglish and sense of humour: have to keep that one, Mark in high form today!
Claude
PS: and excellent french by the way, congrats
Being French, I confess it took me a few seconds to figure out what the hell was meant here... Only to have a great laugh when I got it!
Nice frenglish and sense of humour: have to keep that one, Mark in high form today!
Claude
PS: and excellent french by the way, congrats
Maybe I'm doing what we call "kitchen psychology", but your wordings in the first post: "...It is similar to the front end card which Nelson is providing, except that it uses Fairchild components instead of obsolete and out of production Toshiba parts"... sounds like this is more or less a "replacement" of the original front end avoiding the Toshibas. But everyone that has the kit already has the obsolete Toshiba parts, so Scourge sounded, to me at least, very, very close to what we already had. Obviously, that could be very far from the reality, but until we build them, there is no way of knowing other than by your own description.
For me, I'd like to see what the other topologies bring to the sound, that's why I purchased the "transformerless" options. But Bulwark has had very nice reviews as you mention, so I'm sad not to have included it in this purchase.
