Blockhead "First Born" 18 Schematic
Moderators: zaphod_phil, Daviedawg, Graydon, CurtissRobin, colossal
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mrmojorisin
Blockhead "First Born" 18 Schematic
I heard one of these the other day. It just killed! Anyone take a look inside yet and find out what makes it tick? I would be very interested in the circuit values. Thx, Carl
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Ian
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Blockhead Firstborn Schematic
You could do worse than look at the photos of the circuit in my genuine 18W Marshall on the Gallery (see "Ian's Original 18W";- double-click on any photo to see higher magnifications). Note that the Cab design is identical to Blockhead's Firstborn" (e.g. square-cut edges around the Plexi, full height Plexi etc.).
I can't say what's inside Blockheads clone, however, I did exchange emails & photos with the owner of Solidbodyguitar's original Marshall, and although I promised not to quote them directly (they're not at all keen on Debating Forums or Websites like this one!), I think it should be OK to tell you that their original Firstborn 18W Marshall is identical to mine, including the circuit.
As Graydon & Richie will tell you, I'm no amp builder! But If anything's not clear in my photos you can just post any questions here & I can easily tell you which bits are connected to what!
Ian.
I can't say what's inside Blockheads clone, however, I did exchange emails & photos with the owner of Solidbodyguitar's original Marshall, and although I promised not to quote them directly (they're not at all keen on Debating Forums or Websites like this one!), I think it should be OK to tell you that their original Firstborn 18W Marshall is identical to mine, including the circuit.
As Graydon & Richie will tell you, I'm no amp builder! But If anything's not clear in my photos you can just post any questions here & I can easily tell you which bits are connected to what!
Ian.
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mrmojorisin
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Plexi
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"" (they're not at all keen on Debating Forums or Websites like this one!)""
I didn't know we were a debating forum.. although we do debate a few things. We started this forum to build an 18 watter. I can't understand why they wouldn't like us. If i could get the price from my plexi,as what they get for the ones they have, i'd probably sell it. I do know since we started this forum,we got alot of information on these amps, that most would never have seen,or would ever have known about.
In some of these amps, there are very small part values that are didfferent from one to another. It may be thats all they had on hand when building the amp. but say .0047 to a .005 is so slight it shouldn't make a difference. Besides that, most of the tolerences are 10 to 20% and over time even those can change, so they can have a different sound or tone/gain between one amp to another.
Richie
I didn't know we were a debating forum.. although we do debate a few things. We started this forum to build an 18 watter. I can't understand why they wouldn't like us. If i could get the price from my plexi,as what they get for the ones they have, i'd probably sell it. I do know since we started this forum,we got alot of information on these amps, that most would never have seen,or would ever have known about.
In some of these amps, there are very small part values that are didfferent from one to another. It may be thats all they had on hand when building the amp. but say .0047 to a .005 is so slight it shouldn't make a difference. Besides that, most of the tolerences are 10 to 20% and over time even those can change, so they can have a different sound or tone/gain between one amp to another.
Richie
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Plexi
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Ian
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OK, first note what I said about "NOT being an Amp builder!!" So for heaven's sake don't simply take the following Cap values as gospel, or something might go bang!
But;- all the Caps seem to have their values stamped on them, eg;
the RED DISK-SHAPED CAPS are all as follows;- the three together on the lower edge of the board are each 0.01Mf, same for the one right of the Triangular group of resistors on rhs of board (ie above 1st ECC83), ditto for the cap directly above that ie accross the Pots, same 0.01Mf again for the two either side of the X-shaped group of resistors on lhs (ie above 1st EL84). The other 4 Red DISK-Shaped Caps are all 0.05Mf ie accross the other Pots & above 2nd ECC83. The two big grey coloured Caps at the extreme left can easily be read from my original photos, but the fatter one for example reads 16MFD 450V. The Black boxy-shaped Cap in the centre of the board says 0.047Mf. The grey cylindrical shaped Cap directly above the 2nd ECC83 is 0.02Mf (ie immediately left of Trianguar Resistor group). That only leaves three small grey-coloured cylindrical caps with their printed values facing the board, but I'd need to prise these away from the board to read them (could be done if somebody was really keen). All the Caps say "RS" (ie Radiospares).
Richie;- the phrase "Debating Forum" was mine;- sorry if it "jarred"! But, I've never mentioned 18watt.com by name to anyone, (except to recommend it!) so nobody was taking any exception to this specific Website (how could they??!!). I think the guy who owns that original so-called "Firstborn" just doesn't care much for discussing things on computer websites & didn't want to be drawn into any form of public discussion. That's all! But note that this did NOT come from Blockhead;- I couldn't get any email reply from Blockhead, so I've never spoken to Blockhead at all.
On the contrary, from what I've seen this is one of the few websites where genuine info. is exchanged without contributors trying to be flash and spoiling things with "Expletive-Jargon", and from my lowly position it seems that discussions posted here really are expanding everyone's knowledge, not only for "Newbie" builders who are clearly getting a huge helping hand from much more experienced builders, but also for those of us interested in learning more about old original 18W Marshalls.
Aren't resistor values colour coded? That's a question, I really don't know!
All the best,
Ian.
PS:- Richie;- I'm now "armed" with a copy of Doyle's book, & jolly interesting it is too!
But;- all the Caps seem to have their values stamped on them, eg;
the RED DISK-SHAPED CAPS are all as follows;- the three together on the lower edge of the board are each 0.01Mf, same for the one right of the Triangular group of resistors on rhs of board (ie above 1st ECC83), ditto for the cap directly above that ie accross the Pots, same 0.01Mf again for the two either side of the X-shaped group of resistors on lhs (ie above 1st EL84). The other 4 Red DISK-Shaped Caps are all 0.05Mf ie accross the other Pots & above 2nd ECC83. The two big grey coloured Caps at the extreme left can easily be read from my original photos, but the fatter one for example reads 16MFD 450V. The Black boxy-shaped Cap in the centre of the board says 0.047Mf. The grey cylindrical shaped Cap directly above the 2nd ECC83 is 0.02Mf (ie immediately left of Trianguar Resistor group). That only leaves three small grey-coloured cylindrical caps with their printed values facing the board, but I'd need to prise these away from the board to read them (could be done if somebody was really keen). All the Caps say "RS" (ie Radiospares).
Richie;- the phrase "Debating Forum" was mine;- sorry if it "jarred"! But, I've never mentioned 18watt.com by name to anyone, (except to recommend it!) so nobody was taking any exception to this specific Website (how could they??!!). I think the guy who owns that original so-called "Firstborn" just doesn't care much for discussing things on computer websites & didn't want to be drawn into any form of public discussion. That's all! But note that this did NOT come from Blockhead;- I couldn't get any email reply from Blockhead, so I've never spoken to Blockhead at all.
On the contrary, from what I've seen this is one of the few websites where genuine info. is exchanged without contributors trying to be flash and spoiling things with "Expletive-Jargon", and from my lowly position it seems that discussions posted here really are expanding everyone's knowledge, not only for "Newbie" builders who are clearly getting a huge helping hand from much more experienced builders, but also for those of us interested in learning more about old original 18W Marshalls.
Aren't resistor values colour coded? That's a question, I really don't know!
All the best,
Ian.
PS:- Richie;- I'm now "armed" with a copy of Doyle's book, & jolly interesting it is too!
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Plexi
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"""I'm now "armed" with a copy of Doyle's book, & jolly interesting it is too!"""
Great book, they didn't leave too much out. It has tons of great info.
I think more than anything,we just want to make sure everything is correct. Most of the things you can see, and tell where they go. The only thing thats different on all the layouts and diagrams in the files were..the inputs to the PI.. and the hookup of V3 trem channel(socket and board}. All a person has to do is look at those layouts, and see what needs to be changed. Its not that the amp won't work,as many have built the amp..lol
but its not set up like an original amp. The PI input can make for the channels sounding different. Your pics clearly show where they are coming from and going to.
After looking at all the pics i could find of the real 18s.. they are like this too. Maybe Gabi would like to add a layout change to show the hookups.
I've brought this up a few times,but i can't change nuttin..lol I just changed things on the amps i built.
Richie
Great book, they didn't leave too much out. It has tons of great info.
I think more than anything,we just want to make sure everything is correct. Most of the things you can see, and tell where they go. The only thing thats different on all the layouts and diagrams in the files were..the inputs to the PI.. and the hookup of V3 trem channel(socket and board}. All a person has to do is look at those layouts, and see what needs to be changed. Its not that the amp won't work,as many have built the amp..lol
but its not set up like an original amp. The PI input can make for the channels sounding different. Your pics clearly show where they are coming from and going to.
After looking at all the pics i could find of the real 18s.. they are like this too. Maybe Gabi would like to add a layout change to show the hookups.
I've brought this up a few times,but i can't change nuttin..lol I just changed things on the amps i built.
Richie
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mrmojorisin
[quote="Ian"]That only leaves three small grey-coloured cylindrical caps with their printed values facing the board, but I'd need to prise these away from the board to read them (could be done if somebody was really keen). quote]
Ian, I could only find two of these caps on the board. Where is the third one?
Also, it would be just fantastic if you could post better pics of the pot wiring and also the power tube and preamp tube wiring so we get a good look at all the wiring not on the board.
Your pics are fantastic and a real service. They are mucg appreciated!
Carl
Ian, I could only find two of these caps on the board. Where is the third one?
Also, it would be just fantastic if you could post better pics of the pot wiring and also the power tube and preamp tube wiring so we get a good look at all the wiring not on the board.
Your pics are fantastic and a real service. They are mucg appreciated!
Carl
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Ian
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18W Firstborn
Richie;- quote... “I’ve brought this up a few times, but I can’t change nuttin….lolâ€
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Psalm150
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Wow, thanks for all the info Ian!
Yeah, there is definitely some different wiring going on! I'm with Plexi, we need a layout that shows this.
I'd be really interested to see how that sounds compared with 'Makr D's Original 18w Layout'. All we need are those two sockets, but I guess it'd be better to have a full layout.
I'd go ahead and rewire, but I can't quite make out where everything goes. But it's obvious that it's totally different than what I've got going on!
Yeah, there is definitely some different wiring going on! I'm with Plexi, we need a layout that shows this.
I'd be really interested to see how that sounds compared with 'Makr D's Original 18w Layout'. All we need are those two sockets, but I guess it'd be better to have a full layout. I'd go ahead and rewire, but I can't quite make out where everything goes. But it's obvious that it's totally different than what I've got going on!
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mrmojorisin
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Plexi
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drgork
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While we're on the subject of originals and the Blockheads, does anyone in the group own a Blockhead 18? A few years ago I talked to the guy at Solidbody Guitar and he told me about his personal 2x12 that he would never sell that was the first one (2x12 I think) built. He also told me that the Blockhead guys had examined that amp when they were developing their regular 18's. If anyone has a regular Blockhead 18 and could put up some photos, it would be interesting to compare it to Ian's amp. My hunch is that Blockhead's regular 18 is probably identical to the First Born circuit-wise.
From the gut shots I've seen of other Blockheads, they look pretty straightforward and close to the amps they are based on. A couple have appeared on eBay in the last couple of weeks with good photos.
Ian, your 2x12 is one of the most clean and beautiful examples I've seen. I bet it sounds incredible!
Danny
From the gut shots I've seen of other Blockheads, they look pretty straightforward and close to the amps they are based on. A couple have appeared on eBay in the last couple of weeks with good photos.
Ian, your 2x12 is one of the most clean and beautiful examples I've seen. I bet it sounds incredible!
Danny
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mrmojorisin
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Ian
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18W Firstborn
Carl/Richie;- I think my last reply got out of sequence on this (see foot of page-1 on this thread), but just to “re-Capâ€
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