OK, I see where you're going with this now.
The light bulb limiter is worthwhile to protect the coils in addition to the effect it provides.
Dual tank reverb
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mediatechnology
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Re: Dual tank reverb
The limiter/attenuator part is housed seperately from the tank itself so your not tied to it ,
The Grampian 636 also used the bulb limiter as an overload indicator .
The Grampian 636 also used the bulb limiter as an overload indicator .
Re: Dual tank reverb
Heres the two bulb volume compressor
- Hammond volume compressor .JPG (16.78 KiB) Viewed 11214 times
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mediatechnology
- Posts: 6163
- Joined: Sat Aug 11, 2007 2:34 pm
- Location: Oak Cliff, Texas
- Contact:
Re: Dual tank reverb
R22 and R23 are different values which suggest an effort to introduce some even-order harmonic distortion.
Re: Dual tank reverb
I have a small 5w tube amp with a two bulb limiter(non bridged) and the wirewound pot attenuator built in but its not to hand at the moment .
It works but feels like its missing functionality , a way to adjust the bulbs threshold depending on input power .
In the amp I think I used a three terminal pot , maybe a 50 ohm rheostat directly across the output terminals is better .
So I have the bridged lamps arrangement , an on/off/on dual pole toggle switch and pot or rheostat , what Im aksing is how do I make it so those elements interact in a useful way to create a user experiance .
It works but feels like its missing functionality , a way to adjust the bulbs threshold depending on input power .
In the amp I think I used a three terminal pot , maybe a 50 ohm rheostat directly across the output terminals is better .
So I have the bridged lamps arrangement , an on/off/on dual pole toggle switch and pot or rheostat , what Im aksing is how do I make it so those elements interact in a useful way to create a user experiance .
Re: Dual tank reverb
I took a closer look at the 12V mobile amp today ,
Running off mains power causes a lot of hum due to interactions between the transformers .
On battery zero hum , so hiss becomes the dominant factor .
below is a similar amp to what I have ,
Gain is a bit high as is so I might just wire the input direct to the tone control stage .
One nice thing about the amp is theres no thumps when you power up or down , and no chance of it ever putting DC across the coils .
Running off mains power causes a lot of hum due to interactions between the transformers .
On battery zero hum , so hiss becomes the dominant factor .
below is a similar amp to what I have ,
Gain is a bit high as is so I might just wire the input direct to the tone control stage .
One nice thing about the amp is theres no thumps when you power up or down , and no chance of it ever putting DC across the coils .
Re: Dual tank reverb
Sorry for the rather long gap since posting , obviously theres a lot of interest .
Experiments with the mobile amp were worthwhile , but in reality nowhere near 30w is required .
noise levels in the amp are somewhere in the region of -80db relative to 30W , so that led to a noisey reverb output .
What I have tried in the meantime is using the headphone output from a Soundblaster G6 USB dac , which has analog line input available .
Noise levels are very low and performance is very good driving a 100 ohm tank . Im not sure how well this approach will work with a 10 ohm impedence drive transducer , as I dont have a low-z tank to hand just now .
There are high powered headphone amps with ultra low noise and distortion and high bandwidth available now , theres a variety of models with either external or internal power supply . These look like a good option for a reverb drive amp .
On the recovery side the fet mic booster I showed previously gives excellent performance , the combination of varaible load impedance and added capacitance in the form of of a patch cable provides a very effective means of tone control . Noise is also very low ,but in practice the amount of noise will be determined entirely by the source signal , no real way around that . Guitar amps generally mute the reverb return signal with a foot switch ,
In this case as return cirucit noise is very low you can simply mute the drive signal or turn down the aux send level on the mixer .
Experiments with the mobile amp were worthwhile , but in reality nowhere near 30w is required .
noise levels in the amp are somewhere in the region of -80db relative to 30W , so that led to a noisey reverb output .
What I have tried in the meantime is using the headphone output from a Soundblaster G6 USB dac , which has analog line input available .
Noise levels are very low and performance is very good driving a 100 ohm tank . Im not sure how well this approach will work with a 10 ohm impedence drive transducer , as I dont have a low-z tank to hand just now .
There are high powered headphone amps with ultra low noise and distortion and high bandwidth available now , theres a variety of models with either external or internal power supply . These look like a good option for a reverb drive amp .
On the recovery side the fet mic booster I showed previously gives excellent performance , the combination of varaible load impedance and added capacitance in the form of of a patch cable provides a very effective means of tone control . Noise is also very low ,but in practice the amount of noise will be determined entirely by the source signal , no real way around that . Guitar amps generally mute the reverb return signal with a foot switch ,
In this case as return cirucit noise is very low you can simply mute the drive signal or turn down the aux send level on the mixer .
Re: Dual tank reverb
Id been searching for some reference material to try out the reverb setup and found this ,
Its the takes that would eventually go on to make the doors 'An american Prayer' .
Recorded with that classic unreverberant 'dry booth' LA studio sound .
Im looking a lot like the later era Morrison myself these days ,
https://www.youtube.com/watch?v=tvdjAm0u31k
Its the takes that would eventually go on to make the doors 'An american Prayer' .
Recorded with that classic unreverberant 'dry booth' LA studio sound .
Im looking a lot like the later era Morrison myself these days ,
https://www.youtube.com/watch?v=tvdjAm0u31k