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Everything posted by dave

  1. dave

    Does your “standards” go higher as you upgrade?

    I made a single ended transistor amp, 2 watts, my first independently made up by myself design, in 92. I always thought it it was good, but it has taken me till about 6 months ago to realise it really is one of the best amps I have heard, if a little limited in power. I guess what I am trying to say is that you don't always appreciate what you have at the time.
  2. dave

    Wharfedale Teasdale SP tweaking

    I have a couple of pairs of these, and finally put them in my (not so anymore) valve rig. They don't like my ecl86 se amp. They do love my wide bandwidth, no loop feedback, class mainly A amp however, with a very sweet warm sound that I am really enjoying. However not all sweetness and light. The lovely tweeters are quite directional and the speakers sound quite dull off axis. Which is quite often in my case. Also the upper bass, lower mid sounds a bit muffled, particularly with female speech sounding wrong. I have performed a few measurements, including decay waterfalls, looking for driver problems, but did not see anything obvious. I can't help feeling that there is something going on in the bass mid crossover area. There is also the case. It is 1/2 inch chipboard, and quite lively. This shows up on a waterfall, holding the mic to the side, looking like ripples on water in the wind. The case does not open, so only access through the woofer hole. It could be nice to apply some damping or bracing. I am wondering about putting a tweeter on the back to help the dispersion. Any other ideas how to proceed? It would be nice to help it be just a little less woolly sounding In the bass mid, without upsetting the nice qualities. Male voice sounds adequate, if a little resonant.
  3. dave

    Wharfedale Teasdale SP tweaking

    Very mysterious things have been happening, almost as if the woofer has been bedding in and becomming more like the original one. they have an amazing quality of pure sweet tone, so beguiling, probably the right word actually (just looked it up). But some thing not quite right, in that they are lovely, but not quite like anything else I have heard.... bit of a bump at 500Hz, graphic eq to the rescue again... 4dB cut at 500Hz, and 2 dB lift at 250Hz. I think it sounds a bit more "normal" now. Looks like I am going to have to adjust the cross over a bit. Never mind.
  4. dave

    Ken Ishiwata leaves Marantz

    Just reading the whf article, words of wisdom..... "Unfortunately, specifications don’t tell you about sound quality. That’s not just for DACs, it’s for everything. Those specifications are all based on static measurements, but music is dynamic and there are many other parameters that influence performance. " KI
  5. dave

    Bollox to most of the science - I'd like a new cable

    I see Max has been kind enough to include a description of how it is made. Very tempted to have a go at making a dumbed down, non cryo version my self.
  6. dave

    Wharfedale Teasdale SP tweaking

    Even though I have these running off my graphic eq to tone down the top a little, before I atack the crossover, and a transistor amp... They are now really rather good. Been listening to them all day pretty much. They now have a nice punchy and deep bass, which no longer overpowers the mid and treble. In fact rather the other way, hence the graphic to bring it down a couple of dBs above 500Hz. The un expected bonus of this is that now the sound has quite an acceptable balance in the room off axis, and if I angle them not straight at the listening hot seat, the balance is good there too. The mid and treble are very good, clean, transparent, with good resolving of quiet details. Yesterday, at work, I was wondering what my perfect speakers would actually sound like. I concluded that if they sounded like the sennheiser headphones I was listening to at that moment, that would be good. These speakers do actually sound very much like them now. How's that for instant manifestation?
  7. dave

    On the bench today.......

    Self indulgent thread of half built home projects and repairs.
  8. dave

    On the bench today.......

    Yes, quite right, I was retrospectively refering to the recalcitrant Sony 930 CD player. Forgotten I had left it in a dangling state of unworkingness, from the readers perspective.
  9. dave

    On the bench today.......

    Re cap time. The Sony, in the previous post, starting working again and seems fairly stable now. Unfortunately since it's last thrashing of the eternal cd player, the new direct coupled tube circuit is kicking ass, and leaves the Sony distinctly rough sounding in the highs. Rather deflates any interest I had in listening to it's filters.
  10. dave

    Wharfedale Teasdale SP tweaking

    Well that was quite easy and a little bit sad. I don't have many 8 inch woofers lying around, but I thought I would try an old Yamaha (cheap home cinema) subwoofer driver, I seem to have a number for some reason.... These measurements taken under carefully controlled conditions, it can be seen that the Yamaha (green trace) is about 4 dBs down, but also the breakup is much smoother going into the 500Hz crossover area. Also the bass seems a bit more extended. They have the same DC resistance, which is nice. So i dopped one in and yes, the vocal quality is improved. The tonal balance is a bit leaner now, but the bass is there when needed. I am going to live with them for a bit and see how I get on. I may have to drop the mid and tweeter 2 dB. I will reserve judgment as to whether I like the new version....
  11. dave

    Wharfedale Teasdale SP tweaking

    Probably the woofer. below a nearish field out of the box full range.
  12. dave

    Wharfedale Teasdale SP tweaking

    I think I am going to have to take them off line and do some probing. I have a problem with Helmholtz resonance, that I need to investigate further. Not the port, but the resonance of the bass driver hole. I have a plan now, and I will look in tho the crossover whilst it is in pieces. Been looking at this interesting document: https://lisafea.com/pdf/JMC-Helmholtz_Resonance--Re-ct2.pdf has given me some ideas to try. I was very interested that the Yamaha NS5000 seems to have some countermeasures to these sorts of issues, i think..... https://au.yamaha.com/en/products/contents/audio_visual/ns-5000/technology.html
  13. dave

    Are you keeping your old stuff alive?

    My stuff is pretty much 20-50 years old, except the home cinema, I have a new Blu-ray player and a recent HD projector. Possibly couple of 10-15 year old cd players.
  14. dave

    I dug out something very old from the loft.

    Yawn stretch, was looking forward to something like this.....
  15. dave

    Can anyone help me source 5.5mm copper rods?

    Some of the fuses have been designed to stop the equipment catching fire after something has catastrophically failed. Remember this when thinking of experimenting.
  16. Mostly surprisingly pleasant in a not cd or vinyl, 70's cassette way.
  17. dave

    Not Dead Yet

    I love my cd players. Caveat here is that I embraced DIY nos type circuits back in the late 90's. By far the easiest way to get really decent sound cheaply IMO. If I can stop spending money on hardware for a little while, there are about 10 CDs I want to buy:) I did rip my entire cd pile to MP3, 10 years ago, but couldn't listen to them. And resent having a pc running to access them. Although I do find the streaming idea marvellous, I don't have the personal bandwidth to listen to all that music, most of which I would not like anyway... I may have another go one day. Got a raspberry pi lined up.
  18. dave

    Can anyone help me source 5.5mm copper rods?

    Brass tubes are very reasonable from model shop with adequate current handling and less skin effect, (could even be liquid cooled?), although I would rather use it for screening in my imaginary steam punk style amplifier(?), which I may never get round to making. Humorous comments, This in no way is a recommendation for replacing fuses, just to be clear.
  19. dave

    Can anyone help me source 5.5mm copper rods?

    I have seen a similar misguided attempt once. Sifting through the charred remains of the PCB, pretty much the only thing left intact was the "cost saving" 2mm diameter copper wire "fuse" and the heat sink!
  20. Hi, the holes were leftover from the previous 80's lighting of 10x 60 watt spotlights poking through the ceiling. That is a better price for the adaptor plate, local supplier was asking £9.60 which I couldn't quite stomach at the time.
  21. Yes, you live and learn.
  22. No, the psu is really really shit, it is one of those things you think, do I really want them in the roof space, but they fitted the hole (number one priority at the time), and give a nice even light. Only one psu has blown up so far.... For indication purposes they are a lot like these: https://www.ebay.co.uk/itm/6-X-ROUND-LED-RECESSED-CEILING-DOWNLIGHT-SLIMLINE-PANEL-LIGHT-8W-11W-16W-20W/351178523210?hash=item51c3df024a:m:mmQTslZDltYKBOHn2HjZk5A
  23. This (meaningless in that there is no scale) picture shows the output of my tubed pat 4 preamp. It was a 60's kit, so I have maintained some degree of originality by not re doing all the un screened internal wiring. The mains cable goes to the front of the case for the power switch, and then to the transformer mounted on the back. This is the noise coming from recessed led lighting in the hall. Was quite troubled by this initially, even though not noticeably audible. This noise also makes FM radio reception "difficult". I have fixed it up a bit, but not easy to do in a retrofit. I am going to swap out the lights, but awkward 110mm size for modern down lights. There is also modulation of the mains voltage with a period of 1 second which shows up in output. Turning the hall lights off results in a quieter display. Please try to ignore the burnt wire to the text of the screen.....
  24. I find this vintage extension lead made by my dad in the 60s (upgraded by me with a veneered chipboard base in the 90s) with its rubber insulation produces a more naturally mellow sound, and has a particularly sinergy with vintage valve, equipment, but can also impart a more organic quality to modern solid state gear.
  25. dave


    Can you short out the plugs at the far end of the phono leads plugged into the amplifier, if the buzz returns, you may have lost the ground continuity of your wires, unlikely but possible. Or even check them when an ohm meter. Or try some different wires.