- Tascam DR-05 ticking noises - 13 Updates
- Serious Tube Amp Questions - 4 Updates
- Who wants 1 million euros? - 2 Updates
| adrian@poppyrecords.invalid.invalid (Adrian Tuddenham): Nov 12 04:50PM I have two Tascam DR-05 recorders and they both exhibit the same phenomenon: when they are recording complete silence, there are faint irregular ticking noises on the left channel. This occurs when using an external circuit which disconnects the internal mics, but the circuit only needs to be plugged in, not connected to anything, for it to happen. If there is any sound on the channel, the noise immediately stops, but re-starts about one second after complete silence returns. The noise only occurs if the recording gain is set low; as soon as it is advanced, the noise floor of the pre-amp is enough to stop the effect (it doesn't need to be high enough to mask it). it isn't audible on the headphone monitoring port, even if that is connected to the input of a high gain amplifier; it only shows up when the recording is played back. Can anyone suggest why this is occurring (bearing in mind that it only affects the left channel) and can anyone suggest a cure? -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Nov 12 09:39AM -0800 This is a SWAG - and based on personal history. Back in the day, I had a Tandberg 10" machine, TOL for its day. However, and despite two trips to their Armonk, NY service location, it would 'tick' as you describe on the left channel, and in Fast Forward in a dry room, would shoot sparks from static electricity from the tape to the tape head. I actually drove to Armonk and demonstrated the phenomenon that they stated was impossible. Did not matter which tape was used either. I traded it in on a Revox and never looked back. So, check all your grounding, your patch cords and so forth. That is the best I can suggest off-hand. Best of luck! Peter Wieck Melrose Park, PA |
| adrian@poppyrecords.invalid.invalid (Adrian Tuddenham): Nov 12 07:12PM > it in on a Revox and never looked back. > So, check all your grounding, your patch cords and so forth. That is the > best I can suggest off-hand. I've had similar experiences with static electricity on the drive belts of some tape machines, but this is a hand-held digital recorder with no moving parts. It makes the noises even with a short double-ended 3.5mm stereo jack lead in the input socket and nothing connected to the far end. If the lead is plugged into a passive mixer, the result is just the same and if it is connected to a grounded mains-powered mixer, the result is still the same. I don't think static electricity or anything to do with grounding can be the problem. -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
| dplatt@coop.radagast.org (Dave Platt): Nov 12 11:46AM -0800 In article <1ny62dx.1g2jnyleguzpcN%adrian@poppyrecords.invalid.invalid>, >it is connected to a grounded mains-powered mixer, the result is still >the same. I don't think static electricity or anything to do with >grounding can be the problem. Is it possible to download the resulting digital recording, and examine the waveform with Audacity or a similar tool? A ticking sound might be the result of a one-sample error - either a single bad sample (which would show up as a vertical "tick" on the waveform), or a missing or duplicated sample (which would show up as a vertical jump in the waveform, or a sudden flat spot). In either case, "clocking errors" are what comes to mind for me... a synchronization problem in the analog-to-digital/storage process. Years ago, there used to be a fairly common problem of this sort with long-distance phone calls, where the calls were being transmitted in digital format between phone switches whose internal clocks/oscillators were not properly synchronized. One would be running faster than the other, and occasionally (every few seconds) the difference between the clocks would cause one audio sample to be dropped or duplicated. This resulted in an almost-inaudible "tick" sound. Not a problem for voice calls, really. However, for modem connections (e.g. V.32) which were sensitive to signal phase, it was enough to cause a one-bit error in the data, resulting in a spurious character appearing (most commonly "}" if I recall correctly). If V.42 error control was turned on, the error was detected and the data packet re-sent, so you wouldn't see the bad data, but the retransmission slowed down the connection significantly. |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Nov 12 11:49AM -0800 AUTO LEVEL Using this function, the recording level is automatically increased when the input sound is too quiet or decreased when it is too loud. This function is useful for recording meetings, for example. In this mode, the recording level cannot be changed manually. Precautions for placement and use * The environmental temperature operating range of this unit is 0–40°C (32–104°F). * Do not install this unit in the following types of locations. Doing so could degrade the sound quality and/or cause malfunctions. Places with significant vibrations Near windows or other places exposed to direct sunlight Near heaters or other extremely hot places Extremely cold places Places with bad ventilation or high humidity Very dusty locations. * If this unit is placed near a power amplifier or other device with a large transformer, it could cause a hum. If this occurs, increase the distance between this unit and the other device. * This unit could cause color irregularities on a TV screen or noise from a radio if used nearby. If this occurs, use this unit farther away. * This unit might produce noise if a mobile phone or other wireless device is used nearby to make calls or send or receive signals. If this occurs, increase the distance between this unit and those devices or turn them off. * To enable good heat dissipation, do not place anything on top of this unit. * Do not place this unit on top of a power amplifier or other device that generates heat. Beware of condensation If the unit is moved from a cold to a warm place, or used after a sudden temperature change, there is a danger of condensation; vapor in the air could condense on the internal mechanism, making correct operation impossible. To prevent this, or if this occurs, let the unit sit for one or two hours at the new room temperature before using it. ____________________________________________________________ All of the above suggests that this is an acutely sensitive device. You mention that the ticking happens only when something is plugged in, even if that something is inactive or not plugged in itself. Again, just for giggles, try shorting the inputs, left and right (not left to right). The internal architecture may cause these artifacts to favor the left channel over the right, and I actually find it encouraging that both units display identical behavior. But, what it comes down to if a problem is associated with a specific set of conditions - avoid those conditions moving forward. If shorting the not-otherwise-connected input cord make a change, then you have found the problem. If the problem is associated with the AGC (when the mics are off), you have found the problem. And so forth. Best of luck, again. Peter Wieck Melrose Park, PA |
| Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Nov 12 09:18PM +0100 On 12-11-2018 17:50, Adrian Tuddenham wrote: > high gain amplifier; it only shows up when the recording is played back. > Can anyone suggest why this is occurring (bearing in mind that it only > affects the left channel) and can anyone suggest a cure? Oscillating a bit somewhere? |
| adrian@poppyrecords.invalid.invalid (Adrian Tuddenham): Nov 12 11:18PM > > Can anyone suggest why this is occurring (bearing in mind that it only > > affects the left channel) and can anyone suggest a cure? > Oscillating a bit somewhere? That's what I was thinking, but why only on the left channel? Both recorders behave the same way. -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
| adrian@poppyrecords.invalid.invalid (Adrian Tuddenham): Nov 12 11:18PM > when it is too loud. This function is useful for recording > meetings, for example. In this mode, the recording level cannot > be changed manually. Never used auto, I'm trying to make proper recordings :-) > Precautions for placement and use > * The environmental temperature operating range of this unit > is 0�€"40°C (32�€"104°F). Temp around 18C > Extremely cold places > Places with bad ventilation or high humidity > Very dusty locations. On a clean table > with a large transformer, it could cause a hum. If this occurs, > increase the distance between this unit and the other > device. No power near. > * This unit could cause color irregularities on a TV screen or > noise from a radio if used nearby. If this occurs, use this unit > farther away. I don't have a television. > wireless device is used nearby to make calls or send or > receive signals. If this occurs, increase the distance between > this unit and those devices or turn them off. Nowhere near any other device > top of this unit. > * Do not place this unit on top of a power amplifier or other > device that generates heat. Neither of those. > mechanism, making correct operation impossible. To prevent > this, or if this occurs, let the unit sit for one or two hours at the > new room temperature before using it. It had been in the same dry room for at least 24 hours beforehand. > ___________________________________________ > All of the above suggests that this is an acutely sensitive device. Not really, they all say that. >You mention that the ticking happens only when something is plugged in, even if that something is inactive or not plugged in itself. Again, just for giggles, try shorting the inputs, left and right (not left to right). I'll try it, but the passive mixer terminated it with around 2 kilohms to ground on each channel and plugging and unplugging that didn't alter the amplitude of the noise. >...what it comes down to if a problem is associated with a specific set of conditions - avoid those conditions moving forward. If shorting the not-otherwise-connected input cord make a change, then you have found the problem. If the problem is associated with the AGC (when the mics are off), you have found the problem. And so forth. So far I haven't found any condition when it doesn't occur, other than when there is a signal on the channel and for one second after that (that's why it doesn't occur with the internal mics operating, they increase the noise floor). The first time it made its presence felt was when I was using both recorders together, one with a 12dB attenuator in circuit and the other with a 24dB attenuator as an insurance against overloads when recording an unrepeatable performance from a mixer that could deliver over +12dBm. During gaps in the programme, the machine with the lower level recorded occasional ticking noises, which didn't matter at the time because I had a clean recording on the other machine. I've only just had time to investigate this properly and have discovered that both machines will do it if the signal level is low enough. |
| Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Nov 13 02:09AM +0100 On 13-11-2018 0:18, Adrian Tuddenham wrote: >> Oscillating a bit somewhere? > That's what I was thinking, but why only on the left channel? Both > recorders behave the same way. Spread in components, differences in layout causing parasitic caps an inductances to vary, take your pic. |
| dplatt@coop.radagast.org (Dave Platt): Nov 12 06:12PM -0800 In article <5bea2452$0$25659$e4fe514c@textnews.kpn.nl>, >Spread in components, differences in layout causing parasitic caps an >inductances >to vary, take your pic. Possibly there's some occasional switching noise on a digital or power trace, which is coupled more effectively into the left-channel analog trace going to the ADC? The left-channel trace might actually be acting to shield the right-channel trace from some of the noise. |
| adrian@poppyrecords.invalid.invalid (Adrian Tuddenham): Nov 13 10:59AM > trace, which is coupled more effectively into the left-channel analog > trace going to the ADC? The left-channel trace might actually be > acting to shield the right-channel trace from some of the noise. That could be the sort of thing that is happening - but I wonder why it comes on after about a second's delay? Demonstration at: www.wrightshardware.co.uk/Other/DR0002_0276.wav ...beware loud clicks! -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
| N_Cook <diverse@tcp.co.uk>: Nov 13 12:04PM On 13/11/2018 10:59, Adrian Tuddenham wrote: > Demonstration at: > www.wrightshardware.co.uk/Other/DR0002_0276.wav > ....beware loud clicks! Any chance of cutting a couple of traces and jumpering/swapping left and right to see if the problem swaps channel or stays the same? The mystery ticking noise I had long ago was with magnetic tape car cassette player, no record function, would overlay ticks on pre-recorded tapes. A small bit of ferrite/magnet buried in the pinchwheel rubber was the cause there. |
| John-Del <ohger1s@gmail.com>: Nov 13 08:07AM -0800 On Monday, November 12, 2018 at 11:50:19 AM UTC-5, Adrian Tuddenham wrote: > ~ Adrian Tuddenham ~ > (Remove the ".invalid"s and add ".co.uk" to reply) > www.poppyrecords.co.uk Is there a Tascam specific web group? With two of these doing the exact same *weird* and specific problem, sounds like a design issue. |
| tabbypurr@gmail.com: Nov 12 01:26PM -0800 > I don't blast music in the house anyway so they should be fine. > Cheers, > Eric don't think I've ever seen an isolated variac. Modern speakers are fine on valve amps really. Unless you want excessive volume, or the amp has all of 3W available. NT |
| Terry Schwartz <tschw10117@aol.com>: Nov 12 01:55PM -0800 There are plenty of isolated variacs. I own a VIZ ISO-V-AC II WP-30. Nice unit. |
| John-Del <ohger1s@gmail.com>: Nov 12 04:18PM -0800 On Monday, November 12, 2018 at 4:55:24 PM UTC-5, Terry Schwartz wrote: > There are plenty of isolated variacs. > I own a VIZ ISO-V-AC II WP-30. Nice unit. Very nice. My buddy has a Sencore isolated variac that is similar to your VIZ. I've got an RCA isotap II in my shop (WP-27A). https://community.klipsch.com/uploads/monthly_10_2013/post-14473-13819308189164.jpg Bought it new back in the 70s and use it every work day. No gauges, but it has a tap for monitoring the output. Just meat and potatoes. |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Nov 13 04:05AM -0800 > don't think I've ever seen an isolated variac. > Modern speakers are fine on valve amps really. Unless you want excessive volume, or the amp has all of 3W available. http://www.byan-roper.org/steve/steve-at-play/antique-electronics-and-2/heathkit-ip-5220-variable.html I keep two of these. One in the travel kit, one permanently on the bench. The link shows the innards as well. Most of the VIZ & Sencore units have leakage testing as well. By the way, VIZ, a Philadelphia company was a jobber for RCA, making many of their test equipment under either name. Peter Wieck Melrose Park, PA |
| brix <matlab.user@gmx.com>: Nov 13 11:28AM +0100 On 10/11/2018 10:41, brix wrote: > € 650.000 Ferrara (hand) > € 340,000 Ancona (foot) > € 70.490.000 Total there is an update € 1.500.000.000 Paris (hand) € 30.000.000 Turin (foot) € 25.800.000 Modena (hand) € 17.600.000 Rome (penis) € 17.000.000 Rovigo (hand) € 16.000.000 Gorizia (hand) € 13.500.000 Milan (hand) € 6.000.000 Cremona (foot) € 2.700.000 Cuneo (foot) € 2.500.000 Fermo (foot) € 2.400.000 Ravenna (hand) € 2.200.000 Rimini (hand) € 2.000.000 Ascoli Piceno (hand) € 1.500.000 Chieti (foot) € 1.500.000 Siena (ax) € 800.000 Bari (foot) € 700.000 Verona (foot) € 650.000 Ferrara (hand) € 340.000 Ancona (foot) € 1.643.190.000 Total |
| Rheilly Phoull <rheilly@bigslong.com>: Nov 13 07:20PM +0800 On 13/11/2018 6:28 pm, brix wrote: > € 650.000 Ferrara (hand) > € 340.000 Ancona (foot) > € 1.643.190.000 Total I offer $100 for spam finger. |
| You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com. |
No Response to "Digest for sci.electronics.repair@googlegroups.com - 19 updates in 3 topics"
Post a Comment