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bumpy

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Posts posted by bumpy

  1. On 26/01/2019 at 14:57, Tony_J said:

    It is a technique often used for easily adding extra amplification to car radio systems - basically you use a twin ganged potentiometer, connect the tracks across the speaker terminals and take the low level signals from the sliders. You have to adjust the pot so the signal is at an appropriate level of course. Discussion here: 

    https://www.termpro.com/asp/pubs.asp?ID=119

     Bare in mind I am no expert at this, but my reading suggests the use of 2 resistors if you know the attenuation required. Lets assume line level is 2 V, do we know what speaker level is?

    • Upvote 1
  2. 8 minutes ago, insider9 said:

    Last time I checked Minidsp didn't have any products that offered high level signal. If that was me with the direction you've gone I'd do one of the two things

    - measure bass driver response and mid and design a passive crossover. Guys at duyaudio would help with that 

    - I'd buy two used subwoofers that accept high level signal and take them apart using only amp section for each driver

    Thanks Insider 9.

    Two good recommendations. My initial reaction.

    - measure bass driver response and mid and design a passive crossover. Guys at duyaudio would help with that   - Considering this with purchase of Mini DSP microphone

    - I'd buy two used subwoofers that accept high level signal and take them apart using only amp section for each driver - unfortunately most offer fixed order crossovers.

  3. 8 minutes ago, Tony_J said:

    Pretty sure from a brief scan of the product details that the pwr-ice 125 is low level inputs only. Of course you could create a low level signal from your speaker outputs with a potential divider...

    As a novice in electronics, can you recommend a site that discusses this.

  4. 2 minutes ago, Tony_J said:

    Does the power amp have a pre-out? If so, you could use that into a miniDSP 2x4. That would give you the control you need of crossover frequency and slope, and still give you a single volume control.

    Nice idea, but its very much old school so 'no'

    Psvane.jpg

  5. 12 minutes ago, Tony_J said:

    You will find technical details on the miniDSP site - you can download manuals etc from there. However, the miniDSP devices I have knowledge of (2x4, 2x4HD, DDRC-24) all use low level signals.

    Thanks Tony. I have been registered there for a couple of days but as yet they have not allowed my posting to appear. - Don't they want to sell anything ¬¬

  6. 9 minutes ago, Gizza said:

    Looking at its spec, it would appear not. Do you have a way of feeding it a digital signal? I feed out of my Squeezebox Touch via Toslink into my Minidsp 2x4HD and it sounds superior to me to feeding into the analogue inputs. 

    My main reason for going my way is that the main power amp will control all the driver volumes in one go.

  7. My whole system is designed and built around the concept of minimal messing with the signal (NOS DAC etc).

    For the bass, I look at DSP grudgingly as a means to an end. Rightly or wrongly I think the bass drivers are less susceptible to transmitting any 'digital' distortion to the listener. I would not let digital processing anywhere near the midrange or tweeter.

  8. Nope they use quality passive crossovers and silver wires. I have upgraded the mid range driver to an SEAS Exotic W8 driver which is capable of playing beautifully to lower frequencies than the previous Saba Greencone.

    But, the 15" vintage Altec drivers now overlap too much and 'dull down' the lower frequencies. To determine appropriate inductors and capacitors seems a very expensive experiment, so I am looking at making the crossover to the bass units active with DSP (a little bit like a separate sub).

  9. I need to control my bass driver separately from the mid and tweeter which are working perfectly.

    So I need a low pass filter probably with DSP that is capable of accepting a high level signal from my amp (like most powered subs can). If it has amplification as well that's fine.

    For the low pass filter I need to adjust at least the position of crossover and slope.

    Any recommendations

    seas in location small.jpg

  10. Here is a reply I got from the vendor

    "Thank you for contacting the British Heart Foundation.

    The glass on the valve is no longer glued in place properly, it does not come off completely but the glass is loose at the base of the valve. Both channels on the amp do work and it is a stereo amplifier.

    We have stated that this is a bit quiet, it may be normal but we are not familiar with this amplifier so have put that information to give our customers the best idea on what they are bidding on that we can.

    We hope this information helps and if you have any other questions or concerns please do not hesitate to contact us again. "

  11. Here's a bargain for someone with the confidence to make a bid. 

    http://www.ebay.co.uk/itm/like/AUDION-Triode-Valve-Tube-Amplifier-Silver-Night-SE-Pure-Class-A-545-C79/371718433744?hlpht=true&ops=true&viphx=1&_trksid=p2050601.c100103.m2451&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D37140%26meid%3D1f6fd9832726436396e64cd54b0ad7d8%26pid%3D100103%26rk%3D1%26rkt%3D4%26mehot%3Dpp%26sd%3D371718433744%26clkid%3D7904733415359738319&_qi=RTM2065535

    Here is a reply I got from the vendor

    "Thank you for contacting the British Heart Foundation.

    The glass on the valve is no longer glued in place properly, it does not come off completely but the glass is loose at the base of the valve. Both channels on the amp do work and it is a stereo amplifier.

    We have stated that this is a bit quiet, it may be normal but we are not familiar with this amplifier so have put that information to give our customers the best idea on what they are bidding on that we can.

    We hope this information helps and if you have any other questions or concerns please do not hesitate to contact us again. "

  12. I have owned this Power Plant from new. It betters all the other ways of removing noise from the mains. Easily handled my entire system including a big valve amp. It converts the AC mains to DC, smooths it and reconstructs a purer AC signal. So in effect the mains power starts in your room.

    Essential in these days of digital noise on the mains for TVs and computers. Why waste money on a separate filter for each bit of kit?

    Like all my stuff, its in great condition and has had little real use. It comes with original box and packing.

    http://www.stereophile.com/powerline...lzb5zVa468b.97

    P1060699.jpg

    P1060701.jpg

    P1070138.jpg

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