MichaelW
Well-known member
Nah, I conflated two threads with my response to @Feral Feline. I meant I was on the hook to buy the EF board from you when you got it listed. I want one of those too!
Space Heater - simple tube preamp
- Thread starter vigilante398
- Start date
Feral Feline
Well-known member
Damn!
SERIOUSLY, I need to pay more attention here! I read the Foxtrot thread and knew the requirements — well, I knew it at the time of reading.
I've built two amps, which doesn't make me an expert, I know, but which should mean I know that Tube-Pedals are no mere 9V trifle — I've gotta start paying attention lest I get hurt.
Less clowning, more studying.
vigilante398
Authorized Vendor
Yup, I've been zapped too many times. It was rough at first because I built probably a hundred pedals before I started doing tube stuff, so I was used to being able to poke my fingers inside pedals when they were powered up and handle unboxed PCBs that are powered up. I had to unlearn that habit the hard way. Repeatedly.
Be careful and you should be fine. But don't let a past history of being fine stop you from being careful.
Dan0h
Well-known member
We are on the same page. Just got a 12au7 and a 12at7 in the mail to try in my black eye and space heater and experimental boards. Thinking the same thing. Take a little gain out and this thing will be amazing. The black eye has so much awesome gain available.
I've got 12ay7's in both positions now & it plays Clean to Mean, That's how it's staying.
Dan0h
Well-known member
Will do. My hope is to get the Black eye to sound like the space heater when the gain is down but still have 50% of the current gain when cranking the gain. Then I just need the black on on my board and it can serve both purposes. I too love the way the space heater sounds with a 12ax7 just wish I could get the black eye to sound that good and clean.
MichaelW
Well-known member
Man, now I want to try some 12AY7's in my Black Eye...those are somewhere between a 12AU7 and 12AX7 in terms of gain correct? The gain with the 12AX7's is glorious...rich, thick, lots of harmonics. But also not my style. I have my gain knob around 9 o'clock and that's about the most I'll ever use.
Fuzzonaut
Well-known member
Mmhhh tubes ...
I found some preamp tubes in a drawer, dating back to my amp related tube rolling days and was wondering, if I could use them in a Space Heater, if I ever get around to build one?
Well actually, I pretty much think so, but double checking might not hurt. I have:
- Sovtek 5751
- JJ ECC83S
- Marconi 12AU7
- Tube Town 7025
I found some preamp tubes in a drawer, dating back to my amp related tube rolling days and was wondering, if I could use them in a Space Heater, if I ever get around to build one?
Well actually, I pretty much think so, but double checking might not hurt. I have:
- Sovtek 5751
- JJ ECC83S
- Marconi 12AU7
- Tube Town 7025
vigilante398
Authorized Vendor
Yup, any of those should work without a problem in the Space Heater.
Dan0h
Well-known member
@vigilante398 quick question: my Space heater has very strong (perfection) but not overpowering low end response, but my black eye does not. The BE almost sounds like the low end is cut out at a pretty high level and I understand due to the high gain low end would muddy it up but what cap or resistor value could I easily swap out to let a little more low end through the BE. My goal is to have the lush clean glassy tube sound of the Space heater on my BE when the gain knob is low and then have some of that lovely gain when turning the gain up. I absolutely love the gain sound of the BE and absolutely love the clean sound of the SH but can’t have them both in the same chain due to them not playing nice together. Just wondering if I could swap a resistor or cap on the BE without killing the magic. I am going to try 12au7 and 12at7 combos this weekend but I’m pretty sure the low end will still be missing.
Oh and thank you again for making these available, totally in love with both of them.
Oh and thank you again for making these available, totally in love with both of them.
My findings are by using Lower Gain tubes makes you crank the Gain & Volume more that brings the Low end up!
Dan0h
Well-known member
Sweet. Might have to go swap tubes right now then!
vigilante398
Authorized Vendor
Swapping the coupling caps (22nF 630V) for higher values like 47nF would help, as would increasing the value of the cathode bypass caps (1uF) to 10uF or 22uF.
Space Heater is designed to have a fat low end, it uses 100nF 630V coupling caps and 47uF cathode bypass caps.
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Dan0h
Well-known member
Winner winner. So I dropped in a 12AU7 in V1 and 100% of the low end I was missing returned. Not enough gain so I tried a 12AT7 and holy moly perfection. So for my rig and taste I landed on a TAD 12AT7 in V1 and a Mullard 12AX7 in V2. This combo lets me get from totally clean glass to thick fat gain.
I will say my first combo of a Tung Sol AX7 and old RCA 7025 really made an epic rip your face off 80’s rock/metal distortion that was cool to shred on for a few minutes.
MichaelW
Well-known member
@Dan0h Those are Mullard re-issues right?
I swapped out the 12AX7 for a JJ 12AU7 in my Space Heater and its perfect. with the volume and gain at around 10 0'clock I get no dirt. I can "a hint" of dirt with the Modus Operandi boost on or my General Tso's running a bit hot. But I'm super happy with the sound.
Now that I've confirmed it does that I want I'm on the hunt for a more "mojo" 12AU7.
Not sure if I want to go new re-issue (Mullard/Genelex) or go NOS. I don't see a ton of comparisons on 12AU7 Tubes.
Ideally, I'd like to find an NOS Amperex. Hopefully they won't be as ridiculously priced as their higher gain cousin.
Right now it's the very last pedal before my Apollo Twin X interface. So everything runs into that. including my buffered efx loop with my reverb and delay. Still messing with whether I want it before or after the buffered loop.
I've got another Space Heater board and box coming from Nathan that I'll build with a 12AX7 for a low gain overdrive.
I was thinking about messing with the BE but man, I'm right now I'm loving it with the gain around 9 o'clock. I think I'm just gonna leave it alone.
Everyone needs their face shredded off now and again.....good for the complexion
I swapped out the 12AX7 for a JJ 12AU7 in my Space Heater and its perfect. with the volume and gain at around 10 0'clock I get no dirt. I can "a hint" of dirt with the Modus Operandi boost on or my General Tso's running a bit hot. But I'm super happy with the sound.
Now that I've confirmed it does that I want I'm on the hunt for a more "mojo" 12AU7.
Not sure if I want to go new re-issue (Mullard/Genelex) or go NOS. I don't see a ton of comparisons on 12AU7 Tubes.
Ideally, I'd like to find an NOS Amperex. Hopefully they won't be as ridiculously priced as their higher gain cousin.
Right now it's the very last pedal before my Apollo Twin X interface. So everything runs into that. including my buffered efx loop with my reverb and delay. Still messing with whether I want it before or after the buffered loop.
I've got another Space Heater board and box coming from Nathan that I'll build with a 12AX7 for a low gain overdrive.
I was thinking about messing with the BE but man, I'm right now I'm loving it with the gain around 9 o'clock. I think I'm just gonna leave it alone.
Everyone needs their face shredded off now and again.....good for the complexion
If you score a 12AY7 or 12AT7, You should have a listen with the Black Eye.@Dan0h Those are Mullard re-issues right?
I swapped out the 12AX7 for a JJ 12AU7 in my Space Heater and its perfect. with the volume and gain at around 10 0'clock I get no dirt. I can "a hint" of dirt with the Modus Operandi boost on or my General Tso's running a bit hot. But I'm super happy with the sound.
Now that I've confirmed it does that I want I'm on the hunt for a more "mojo" 12AU7.
Not sure if I want to go new re-issue (Mullard/Genelex) or go NOS. I don't see a ton of comparisons on 12AU7 Tubes.
Ideally, I'd like to find an NOS Amperex. Hopefully they won't be as ridiculously priced as their higher gain cousin.
Right now it's the very last pedal before my Apollo Twin X interface. So everything runs into that. including my buffered efx loop with my reverb and delay. Still messing with whether I want it before or after the buffered loop.
I've got another Space Heater board and box coming from Nathan that I'll build with a 12AX7 for a low gain overdrive.
I was thinking about messing with the BE but man, I'm right now I'm loving it with the gain around 9 o'clock. I think I'm just gonna leave it alone.
Everyone needs their face shredded off now and again.....good for the complexion
I'll be surprised if you take it back out!
MichaelW
Well-known member
"Don't TEMPT ME FRODO!"
Dan0h
Well-known member
Yes. The mullard is a new issue version and sounds great. I did have an order with a NOS tube seller that went south fast and took me weeks to get my $ back. After that I decided to stick with new issue tubes from legitimate vendors that have been around for years.
The old RCAs are Truly amazing but finding a “real” one for a reasonable price is next to impossible. And the difference is very incremental for what the cost is. I have a real RCA 7025 in my West amp from the 70’s and have pulled it and tried it in other amps and it makes anything it is in sound like perfection to my ears. But I have bought a couple “used” RCA 7025s and none of them have the same sound. I do notice that these TAD tubes, first time I’ve ever tried them, are very clean low noise but do seem to have a low end boost in their sound which is cool but seems strange because no other tube I’ve ever played does that. It also just might be the extra headroom from being lower gain tubes causing the boosted low end, I haven’t tried any other branded at7 or au7s. With that said though I’ve decided to run with the TAD at7 as the gain stage in my 1st Black eye build.
The bummer… is now I have all these tube I’m going to have to build more tube pedals… hehe.
