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Post by porkyman on Mar 21, 2015 0:24:44 GMT -6
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Post by rocinante on Mar 23, 2015 18:42:37 GMT -6
Gustsv put that together cause many of us wanted stereo (or dual channel) pultecs but were experiencing noise issues. $680 is probably a low figure albeit not by much. One can use edcors to shave off a buck but like you said a lot of the sound is in the transformers. Ive built g pultecs with both lundahl and edcor xfmrs (lundahls were better sounding imho) and also don audio and carnhill inductors and i think they are just great. Im sure the Warm will be awesome. Both the wa76 and the wa12 sure as hell are. But lets not totally fool ourselves, neither the Warm or Gyraf are actual pultecs.
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Post by porkyman on Mar 23, 2015 20:30:33 GMT -6
does this one have noise issues or previous models? this one is a complete kit. comes with lundahls. 640 euro. i dont think theres an option for edcors.... lets just say case, hardware, shipping etc. round up to $800. thats still roughly around the price of a single channel Warm. i really want that Warm but i think im gonna give this thing a go....
400vdc though!!! scary!!!
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Post by rocinante on Mar 24, 2015 8:15:20 GMT -6
No im sure there is no issues. People had put two g-pultecs in one case against Gustav and Jakobs warnings and some had noise.
If this is you first diy piece; dont do it. Jeff at Capi is the best way to get started. Or like many others a gssl. You'll just end really frustrated and very possibly hurt. Ive zapped myself doing a pultec. Not fun.
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Deleted
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Post by Deleted on Mar 24, 2015 14:02:20 GMT -6
As always:
No way start with a tube project if you are going for a first time DIY project.
You need enough knowledge and skills to stay calm and reasonable while building, and check seriously what you want to do next for your own safety. Or you will most likely zap yourself during a build. Which is potentially seriously dangerous.
Therefore, if i read it right, Gustav doesn't provide a step-by-step build guide.
If you don't know enough about electronics to get the build working from the schematics and the selected parts and pcb, you would be most probably not at the point to build a high voltage tube device...
100% Fictional dialogue that could be based on actually received PM's from other diy forae during the years...:
Question:
"Hi xxx, i saw this cool tube <insert device here> (on your webpage)/(in the forum) and want to build this sucker! I have bought a soldering iron and a multimeter and some solder. Could you provide me a build guide? Would be best with hi-res pics, because i never build such a thing before.
Answer:
"Sure i could. And i most probably would never hear from you again, and you would not bother me anytime later with questions about other projects anymore. If i would want to do this, i would tell you to build the PSU first and be done with it (and everything else). But - i am nice. And therefore there will be no build guide...but i can recommend you a much less dangerous first timer project..."
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Post by tonycamphd on Mar 24, 2015 15:33:38 GMT -6
yes, this i no joke, it's a different level of electrocution, getting zapped from a 120v ac wall outlet in USA is childs play compared to 400vdc!!!! If it DC bites you hard enough, you're dead. Be VERY VERY careful, and assume nothing.
I got barely tagged by JK's MKU47 plugging the mic in with the PSU on(364vdc), and it brought all 230lbs of me to my knees in an instant! my hand hurt for a week, and I consider that outcome as lucky! Never plug a tube mic in with the psu on..never!
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Post by porkyman on Mar 24, 2015 18:15:17 GMT -6
ive built a lot. capi, hairball, sound skulptor, serpent, aml, etc. i just finished an mk47. that was the first tube project i have done. ive been avoiding anything tube because of the high vdc. i hate electricity.... im pretty confident i can build anything now but that doesnt mean its not scary.
thanks for the input guys.
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Post by Deleted on Mar 24, 2015 23:58:41 GMT -6
Hi porkyman, yes it's a bit scary nevertheless. That said, in the old days, everything was "tubes", so are amps, and if you got quite some skills from your builds, i can assure you i saw nothing from Gustav that wasn't well done/well selected. So i would say, if you want that pultec clone, give it a go...! |
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Post by rocinante on Mar 25, 2015 8:17:16 GMT -6
Porkyman,
Pardon me for assuming it was your first build. Build away Im sure its awesome. I never build kits anymore as its more fun figuring it out through research.
i had thought i had discharged the srrp caps once. My hands literally threw the board involuntarily to the ground as a healthy bit voltage got shot through me. Wozers.
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Post by EmRR on Apr 21, 2015 6:16:04 GMT -6
You gotta remember: all DIY in a previous era was with high voltage. I think the first things I built or restored in the 90's (not 1890's) were all tube pieces. You just gotta pay attention. I'd rather work on high voltage than garbage disposals or lawnmower blades.
As said, mimicking the EQ curves is relatively easy, the amp sound is not. The only DIY versions I've used are the SS type Analog Allstars PEQ and the IOaudio MEQ. Both work fine, neither sounds like the real Pultecs I've driven. Most of the sound is the audio transformers, then the inductors, IMO.
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Post by svart on Apr 21, 2015 7:18:17 GMT -6
I once put my arm across 1kV that was on a capacitor. It wasn't so much of a shock as it immediately blew two small chunks out of my arm due to the joules discharging from the cap. My hand was floating between numb and pins-and-needles for a week afterwards.
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Post by EmRR on Apr 21, 2015 9:00:20 GMT -6
How's the arm now? Still show scars? You are playing with the big boys if you are up around 1kV, for sure. That's serious power amp or transmitter territory. The highest I can think of in small signal audio is around 450V at the PSU in some limiters, and those are really 10W power amps. That could take you out, usually something around 120mA available there. They almost always have bleeder resistors that draw down pretty quickly, so as long as you don't dig around stupidly with power on, the are reasonably safe to work on. Something like a Pultec, much lower voltages and current capacity. The only thing that ever meaningfully bit me was an Ampeg V4. We could always cook a finger off getting a screwdriver and wedding band caught in the wrong place on a car battery too, low voltage, massive current.
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Post by mulmany on Apr 21, 2015 9:46:00 GMT -6
EmRR, I welded my Dmm probe to my V4-B while testing... got it a little to close. Those things were built right on the edge of component ratings. That gave me a big scare, also forced me to tighten up my safety protocol for myself.
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Post by EmRR on Apr 21, 2015 10:44:12 GMT -6
Yeah Patrick, there seem to be a lot of V4 stories out there. On the edge of ratings, some parts rather close together.
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Post by svart on Apr 21, 2015 11:28:02 GMT -6
How's the arm now? Still show scars? You are playing with the big boys if you are up around 1kV, for sure. That's serious power amp or transmitter territory. The highest I can think of in small signal audio is around 450V at the PSU in some limiters, and those are really 10W power amps. That could take you out, usually something around 120mA available there. They almost always have bleeder resistors that draw down pretty quickly, so as long as you don't dig around stupidly with power on, the are reasonably safe to work on. Something like a Pultec, much lower voltages and current capacity. The only thing that ever meaningfully bit me was an Ampeg V4. We could always cook a finger off getting a screwdriver and wedding band caught in the wrong place on a car battery too, low voltage, massive current. This was like 20 years ago, the arm is fine now! Just a tiny pock mark left to remind me of this. This was an old tube TV. I've also been shocked by the 25KV from a TV/monitor but it's extremely low current and is more akin to a serious static discharge from rubbing your feet on the carpet. Anyway, caps not only hold a voltage, but the charge they hold can dump instantaneous currents in the hundreds of amps into a load for a very short period of time, which can burn you as well as shock you! I consider them more dangerous than straight current, which can be interrupted by fuses, etc. |
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Post by EmRR on Apr 21, 2015 12:36:47 GMT -6
True. Many a screwdriver tip has been marred discharging caps as a short, rather than through some resistance.
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