I have been using DSP since my solidstate days, and have enjoyed adding it to my tube setups. Anybody else use DSP in front of your tube amps? I had Chromecast audio feeding a miniDSP nanodigi, which went to Khadas tone board DAC and then to the 8900. I wanted to experience 24/192, so I replaced the CCA with raspberry pi 4 running Moode audio last week. I use the Camilla DSP inside the OS now, feeding the Khadas tone board (I upsample everything to 24/192 in Camilla DSP). I accidentally seem to have stumbled into audio nirvana. This setup through the 8900 and my open baffle Lii audio f18 is just magical (I DSP'd the system ruler flat from 25 Hz to 16 KHz at my sitting position). I know purists look down upon DSP, especially before tubes, just curious if anyone likes DSP.
Yes, I use a DSP for room EQ and volume controls. My setup is Volumio on a rpi3 with hifiberry DAC+DSP. This drives a TU-8800 with GEC 12AX7 and Tungsol KT-120 tubes. I have recently upgraded from Axiom M3 bookshelf speakers to Axiom M60 floorstanding. DSP filters are calculated using REW. I only have the DSP level frequencies between 20 and 150Hz. My room has a nice 12dB "boom" between 40 and 50Hz that the DSP takes care of quite nicely. Source material is mostly FLAC from hdtracks.com, some self ripped from CD.
I bought the new speakers wired for bi-amping, but after upgrading to the KT120s, I'm questioning if it's needed.
I bought the new speakers wired for bi-amping, but after upgrading to the KT120s, I'm questioning if it's needed.
I don't use DSP in front of my amp (TU-8200), however, downstream of the amp I split the signal off into two feeds - one to my speakers, and the second goes through a speaker to line level converter, then to a MiniDSP 2x4 UHD which has both high pass (-3dB at 15dB) and low pass (-3dB at 85 Hz) filters, room correction (measured using Room EQ Wizard), and a slight delay for phase correction (0.8ms IIRC) at the low-pass filter cutoff relative to my mains. The summed (now mono) line level feed from the MiniDSP then feeds a pair of subwoofers.
I run my speakers (Klipsch Heresy III) full range with no DSP and I think they sound great in my room, but the DSP for the subs was the missing piece in my audio system - the integration of the subs was a mess without the DSP both in terms of getting the phase correct and addressing the inevitable peaks and valleys in the 20Hz to 80Hz range.
For example on side of my listening room has a pair of French doors into another large room. Using 1/3 octave smoothing over a handful of measurements I could see the effect of having both doors open, one of the pair open, or both closed on the bass in the room. I also discovered that even with dual subwoofers I have a dip of around 6dB at 52Hz in my room which the DSP easily addresses.
In summary - I'm a fully analog signal path purist and find that I get a huge benefit from using DSP on just the subwoofers.
I run my speakers (Klipsch Heresy III) full range with no DSP and I think they sound great in my room, but the DSP for the subs was the missing piece in my audio system - the integration of the subs was a mess without the DSP both in terms of getting the phase correct and addressing the inevitable peaks and valleys in the 20Hz to 80Hz range.
For example on side of my listening room has a pair of French doors into another large room. Using 1/3 octave smoothing over a handful of measurements I could see the effect of having both doors open, one of the pair open, or both closed on the bass in the room. I also discovered that even with dual subwoofers I have a dip of around 6dB at 52Hz in my room which the DSP easily addresses.
In summary - I'm a fully analog signal path purist and find that I get a huge benefit from using DSP on just the subwoofers.
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I just bought a 2x4HD to help me decide what kind of XO to use on Khorns. If it wasn't for the big time mis-alignment between bass horn and mid horn I may not have bothered but it's a first jump into the digital domain for me and I'm curious to find out what I learn from it. the khorns have not been finished yet and they will be driven by a range of amps, possibly also becoming part of my HT system.
I'm building a tube pre-amp and I'm considering including a Tape loop into which the DSP could be introduced should I want to try it out for things like bass boost, room EQ or even time alignment duties without using it as an XO.
I'm building a tube pre-amp and I'm considering including a Tape loop into which the DSP could be introduced should I want to try it out for things like bass boost, room EQ or even time alignment duties without using it as an XO.
The miniDSP offerings are a mess - the 2x4 HD uses an in-built DAC that is very ordinary to downright bad (depending on the quality of DACs you are used to). The nanoDigi, now discontinued, offered all digital input and outputs so you can use an external DAC, but no USB (even to setup test tones to dial the DSP you need to find a digital input. It is a hassle to connect the computer to an optical audio out to just setup the DSP). The 2x4 HD offers FIR filters, the nanoDigi does not (but has 18 IIR banks compared to 10 in the 2x4 HD). Neither offer convolution filters, which I have now discovered are an absolute next level in wave shaping. For x-over and subwoofer duties I think the miniDSP are very good, not for what I was trying to do, which was to eq the entire spectrum flat.
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@jamesemucc is absolutely right. In the end the gains from the DSP - fixing all the unevenness - could be vastly more valuable than the native system performance. I was being nitpicky in my comment. The 2x4 HD is a powerful product because how easy it is to integrate into the audio chain and how many problems it solves.
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I will start any experiments with an open mind then, but I will give this unit the benefit of doubt, meaning that I expect to find it a good addition although the passage of time will be the final arbiter, somehow there’s always a reckoning eventually before a component has earned a permanent seat.
On occasion sometimes, I use a Hughes design of Sound Retrieval System (SRS) through one of my tape loops to give an expansive 3 dimensional quality and depth to the sound.
Even has a setting that enhances mono sound.
I built the system into a chassis along with a multi-function tape record/play dubbing arrangement, so I could also add the SRS into recordings.
For instance, if a tape/CD is played in a car, or a portable boombox, the music surrounds you, makes a boombox seem 6 feet wide.
Even has a setting that enhances mono sound.
I built the system into a chassis along with a multi-function tape record/play dubbing arrangement, so I could also add the SRS into recordings.
For instance, if a tape/CD is played in a car, or a portable boombox, the music surrounds you, makes a boombox seem 6 feet wide.
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Yeah, when I DSP'd my F15s for a more flat response, they seemed to even get even more transparent.
Lately I've been working with a USB to I2S with better clocks (thanks to a forum member who helped me out with hardware and clock improvements, which I could barely implement but managed) and I have a JLSounds USB to I2S converter a day away from my doorstep.
That JLS is destined for the Lii F15 setup. The I2S input amp driving has DSP, as well as the W10 system media source. The amp DSP for EQ between drivers (there's an 18" helper) and the Windows "Equalizer APO" for overall EQ.
Going out of orbit even further, I've been experimenting with high impedance drive using a backward connected line matching transformer - with 8 Ohm ballast resistor - to good effect in the bedroom system and I just might give that a go on the Liis as well. One of the criterias is met, as the Liis are crossed well above their Fs - and they and the helper woofers have their own amp channels. Hoping to get the 'ol flea power tube sound from a class D output.