blackheart "little giant" BH5H

[DummyLoad]

ok, so while surfing the local CL ads in search of a 12" eminence speaker, i run across this ad that has several models and all are stated to be as new, if not new. listed in the same ad was a couple of amps that needed repair, one of which was a blackheart "little giant" BH5H head. i made the guy an offer on the speaker and the amp and he bit, so then i make arrangements to meet. driving out to his place in the nicer part of the hill country, i finally arrive, he introduces himself and i don't place the name at all. some small talk later i ask him about his amp building, he replies "i designed the blackheart you're buying"; my name is pytor belov. i design the new gibson stuff and some of the new ampeg. WOW! cool! major amp geek!

anyway, i spent more than i intended (bought some switches, second speaker, and NOS sockets) we made arrangements for me to return to help him "clean out the garage" at the end of the month.

ok, about the amp now, the OT was blown and missing altogether, and the PT was thought to be blown, but i cannot find any indication of that. i ordered a "classictone" 15W upgrade champ OT from mag comp. i'll post up results after it's repaired.

i had some spare time, and since i can't seem to locate a schematic online (no, i haven't called india! sheesh!), hell, it's a simple little 2 tube head - i'll reverse engineer it. attached is the fruit of that effort.

--DL

[HotBluePlates]

... he replies "i designed the blackheart you're buying; my name is pytor belov. i design the new gibson stuff and some of the new ampeg." ...

How do I get that job? 

Is the 51Ω and 10nF really attached to the sleeve contact of the input jack and not the switched contact? It would make the most sense of that was running from circuit ground on the board to chassis ground (it's how you do a good ground lift, while keeping RF passing from circuit ground to the chassis and ground wire).

[smackoj]

great! did you invite Pytour to join the forum? I think we still have one slot left for 'major tube geek'

 

[alerich]

I think he designed the Epiphone Valve Junior amps, too. I had a Blackheart 15W head I got through a CL trade a few years back. Nice clean tones but the crunch tone didn't do much for me. That was an extremely well built amplifier. Heavy PCB board. Properly rated resistors. The modders like them. At the time I was looking for a higher wattage head. Blackheart made a 100W head called the Hothead. It was as well built as the other Blackheart offerings and priced very reasonably but it went nowhere in the marketplace and was discontinued. I wanted to like that head but I just couldn't find enough love to pull the trigger. I probably should have. Several retailers were blowing them out at that time for $400 with free shipping (I think the original price was $700).

[DummyLoad]

... he replies "i designed the blackheart you're buying; my name is pytor belov. i design the new gibson stuff and some of the new ampeg." ...
How do I get that job?    

i guess have lots of charm, become a russian, & practice your slavic accent while speaking english - probably helps, no? lol!

Is the 51Ω and 10nF really attached to the sleeve contact of the input jack and not the switched contact? It would make the most sense of that was running from circuit ground on the board to chassis ground (it's how you do a good ground lift, while keeping RF passing from circuit ground to the chassis and ground wire).

it's wired as you say - i drew it correct on the hand draft but transposed to CAD incorrect. fixed it and attached corrections. i pulled the PCB & will post pics of the solder side 7 comp. sides. it's nothing spectacular - 62mil (1/16") stuff everyone else uses. it's just red in color - must be mojo. <rolleyes>

grounding scheme updated - i should have pulled the PCB rather than make assumptions. note that all nodes share the same ground plane on the PCB. the ground lift/RF leak network is a second ground point. my apologies for any confusion.

--DL

[DummyLoad]

great! did you invite Pytour to join the forum? I think we still have one slot left for 'major tube geek'

 

quote - " i stay away from forums" can't blame him. this is the only one i frequent - very mellow, helpful, and kind people. 

--DL

[SILVERGUN]

Thanks for sharing that...

I plugged into one of these used at GC about a month ago and it left a great impression on me.....great to know I can build it now if I want to  .....it's number 8 on the list!,,,so I'll get to it around 2015 

I thought it was the best sounding little head I had tried (very open and pure sounding), and it really surprised me that they were only asking $199 used......went back a week later to get some strings and it was gone, so I wasn't alone...

[PRR]

You have R1 twice, both at 1Meg.

Seems unlikely, 1Meg to Grid.

[DummyLoad]

You have R1 twice, both at 1Meg.

Seems unlikely, 1Meg to Grid.

right - it's R2 and it's a 33K.

--DL

EDIT: Bass pot value, PT primary scheme corrected, added PT primary & sec. DCR measurements.

[HotBluePlates]

I think it's interesting that it's basically a blackface Champ with an EL84 and some common tweaks and trickery, but especially the extra filter node ahead of the plate supply node like we commonly recommend for SE amps.

[DummyLoad]

I think it's interesting that it's basically a blackface Champ with an EL84 and some common tweaks and trickery, but especially the extra filter node ahead of the plate supply node like we commonly recommend for SE amps.

agreed, i like the power supply too, but doesn't the champ lack a tone network? my first thoughts were that it's an AB763 pre, with marshall-like values in the tone stack...of course, the summing amp and PI are not needed, so mr. belov grafts in a self bias high gain SE output stage.
can't wait to get it going; form the youtube clips iv'e heard, it's seems like a decent enough little amp. lastly, not sure that the iron needs upgrading, given that this one is missing it's piece, i have a mag components 15W SE classictone on the way and the PS filters are being replaced with nichicon low-z, high temp (105c) types.

--DL

[HotBluePlates]

AA764 Champ

The BH5H has the values recommended by Ken Fischer as a way to reduce mud in the blackface tone stack.

[DummyLoad]

i see, now - a vibro champ.

--DL

[HotBluePlates]

Oops... that was the schematic Hoffman has under "Champ".

Blackface and silverface champs also had treble and bass controls, without the trem. Midrange was fixed.

[SILVERGUN]

Just as another point of reference for what it's worth,,
I had built this amp last month and thought it sounded really good and initially went into GC to confirm this belief......
BUT, after playing that BH5H, I was left second guessing myself....

So what I'm trying to say is, IMHO this Blackfart sounds better than my Custom Champ (based on Blackface champ).....I didn't want it to be true,,,but it is  

[DummyLoad]

Blackface and silverface champs also had treble and bass controls, without the trem. Midrange was fixed.

fender got fancy - i don't know about you guys, but i prefer the tweed champ without tone control(s). IOW, the 5F1 ckt.

respectfully,

--Pete

[DummyLoad]

Just as another point of reference for what it's worth,,
I had built this amp last month and thought it sounded really good and initially went into GC to confirm this belief......
BUT, after playing that BH5H, I was left second guessing myself....

So what I'm trying to say is, IMHO this Blackfart sounds better than my Custom Champ (based on Blackface champ).....I didn't want it to be true,,,but it is  

you don't have any voltages indicated in your schematic; is it possible that the 6V6 is running too cold? i see 600R under the 6V6, IME, SE sounds best for guitar amps if you push the output tube as hard as possible. if the amps plate B+ is around 320V-340V try fiddling with the cathode R of around 470-500R.

respectfully,

--DL

[SILVERGUN]

i don't know about you guys, but i prefer the tweed champ without tone control(s). IOW, the 5F1 ckt.

Never had the pleasure of trying one,,,BUT, please give us your opinion of how this Fart stacks up when you get it running

For me the Champ makes a great bench tester for 12AX7 tubes to go into my other builds....
I was able to weed through some pretty weak sounding new production TungSols to get to a nice 7025 Sovtek (unfortunately I started late and have ZERO collection)

[SILVERGUN]

you don't have any voltages indicated in your schematic; is it possible that the 6V6 is running too cold? i see 600R under the 6V6, IME, SE sounds best for guitar amps if you push the output tube as hard as possible. if the amps plate B+ is around 320V-340V try fiddling with the cathode R of around 470-500R.

Great point, and funny you say that...when I first built it I only had a 470R in stock so I put it in.....but my B+ on the plates was 470ish,,,and I had plate diss. at 18W (It sounded good for a while, but I knew it was high,,and eventually saw an internal arc while play testing at full output)
I put a temp. 1K in there and that cleaned up the numbers, but I read (Aiken?) where that was the "wrong" approach....

So I put a Vintage Voltage adapter on the input as a bucking xfmr, and that brought the B+ down to 380ish and the diss. right around 14W(with 470R back in there),,,and the amp sounds smoother with less ice-pick at high volume......
I'm also much more comfortable with the lowered B+,,,,,and learned a cool lesson by accident----just by lowering the B+, the current will lower "automatically" as a by-product....(may be elementary to most, but a light bulb for me )

I went back and adjusted schematic to actual value and added voltage

[DummyLoad]

please give us your opinion of how this Fart stacks up when you get it running

i would be happy to do so, however, please not that the OT won't be the same as the one you heard, so the baseline for comparison will be skewed, however, nor do i expect a "WOW" factor with the mag components classistone part...   

respectfully,

--DL

[SILVERGUN]

I used a cheap OT,,,so maybe that's where some of my wow factor went as well

[DummyLoad]

I used a cheap OT,,,so maybe that's where some of my wow factor went as well

maybe

experiment with other types. :-)

[fuzz]

I had a litte giant 5W , I still have it but the circuit isn't here anymore . The build quality was really nice . Components were "standart" but for the price nothing to complain...

I've wrote down the voltage on a schematic copy (of the "official" schematic ) , if that's can be helping



I still have the transformers hanging around by the way   (the PT must be used in other product , its  secondary has a center tap and 5V wiring , certainly for a rectifier tube) .


 

[DummyLoad]

I've wrote down the voltage on a schematic copy (of the "official" schematic ) , if that's can be helping

thank you very much. it does help - my PT was fried -

i used a hammond 270CX for replacement - B+ was 365 @ first filter and 325V @ OT tap - so close enough.

the PCB is cheap, as in as cheap as chinese crap gets - very thin copper eutectic. i ended up scrapping mine, i un-soldered/soldered one too many times on three of the OT/PT pads lifted off, got frustrated and scrapped it. i loath PCB amps to begin with; it was meant to be so. turret board in the works later - working on a standel and GA70.

amp sounds pretty good, i had mine up for a few minutes, but nothing spectacular though. i played it though an eminence red coat 12".

respectfully,

--pete

[Willabe]

With the turret board you can do what you want with out worry.


           Brad     

[DummyLoad]

With the turret board you can do what you want with out worry.


           Brad     

agreed!   

--pete

[fuzz]

the PCB is cheap, as in as cheap as chinese crap gets - very thin copper eutectic. i ended up scrapping mine, i un-soldered/soldered one too many times on three of the OT/PT pads lifted off, got frustrated and scrapped it. i loath PCB amps to begin with; it was meant to be so. turret board in the works later - working on a standel and GA70.

 apparantly they have changed a lot during production time. I bought mine "second hand" few years ago and it had JJ tube in it (still got the EL84 running in an amp) and the news ones didn't have these tubes . The PCB was really strong even after my serveral attacks on it . I did few modifications on it and the PCB never gave up (but PCBs aren't great for modifications , really boring to work on it ).

for the PT if my memories are right , the AC voltage (before the diode bridge) was really high , around 400V or so hence the 470R/5W resistor at the begining of the HT line. I'll try to find the exact information that I put on an other forum when I was working on mine.

Are you looking for the exact PT ? I read somewhere that Crate stopped doing blackheart but I MAY be wrong. So maybe they can have some transformers left , and that they can sell or give for repair (yes I'm certainly naive  )

[HotBluePlates]

for the PT if my memories are right , the AC voltage (before the diode bridge) was really high , around 400V or so hence the 470R/5W resistor at the begining of the HT line.

I'd bet the 470Ω resistor was to allow a C-R-C pi filter before feeding the output tube plate.

Many folks who've built their own Champ-style amps have found the hum level to be unacceptable, especially when using a speaker that has response over the full guitar range. The cure for them was to add a C to ground and a series R before the existing filter cap, which reduces ripple before the output transformer.

I see the BH5H as having this upgrade from the get-go.

[DummyLoad]

Are you looking for the exact PT ?

no. i have a replacement - as stated earlier, i'll be using the hammond 270CX and just need to mod the chassis for fitment. your voltages readings on your schematic confirmed i was near the mark (slightly higher) even with the lower secondary voltage rating - the original is marked 275-0-275 and i'm using a 250-0-250 likely with a higher current rating. the quality of the original wasn't impressive; 3 secondary fuses a primary fuse and it still fried. OT was fried and long gone when i got it, so i grafted in a magnetic components classictone 15W SE champ upgrade. sounded OK, just not enough oomph.

Crate stopped doing blackheart

don't know either... the crate website doesn't list them in the crate product line-up and the blackhearteng.com website is serving off malware.

pyotr (the designer) is selling off some more stuff this weekend and i'm meeting with him tomorrow to pick up a few more parts and a couple of speakers. if you have any questions for him regarding blackheart equipment, i'd be happy to pass them on.

respectfully,

--pete

[DummyLoad]

I see the BH5H as having this upgrade from the get-go.

mine had a 1K 5W there - perhaps to comp for the higher sec. volt rating.

--pete

[OldHouseScott]

I got to meet Pyotr at the Southeastern Guitar and Amp Show (SEGAS) a few years back. He was in the Ampeg booth, showing off the GVT amps he designed. Really nice guy.

[DummyLoad]

I got to meet Pyotr at the Southeastern Guitar and Amp Show (SEGAS) a few years back. He was in the Ampeg booth, showing off the GVT amps he designed. Really nice guy.

that he is. quite a likable chap. he's kick-starting belov group, LLC, consulting.

http://www.belovgroup.com/

--pete

[DummyLoad]

mr. belov found a PCB panel for this amp. he gave me the panel (2 ckt cards) and all the pots and jacks to populate the 2 PCBs. almost done with the construction of one - missing the fuse holders; they are on order. he could't locate a replacement OT so the classistone goes back in her.

in the pile of stuff, he bequeathed to me the original prototype head cabinet, speaker cabinet, and the bare chassis. the speaker cabinet was finished in purple tolex.

this amp is now a restoration project and i plan to keep her. pics when she's finito.

respectfully,

--pete

[DummyLoad]

this amp is running and buttoned up.     used a hammond 270CAX for PT and magnetic components classictone 15W OT strapped 8K. mounting the PT only required 3 holes be drilled as one side fit, the OT fit with just one hole drilled and the mounting flanges opened up a bit.

attached is final schema with telemetry. i installed some minor tweaks for the bypass caps. the grid stoppers are 2k2 because i ran out of 1K5. 

--pete

[baerster]

I just bought one of these at a used musical instrument store. Someone tried to mod it but did not finish the job, so it works OK but the tone controls don't function at all. The mod has three switches placed in the front, and it looks like the treble pot was replaced. I am inclined to try reversing this mod so it works as originally designed, but I wonder if anyone here has heard of common mods to this amp.