Big John
pfm Member
Relived that I'm not the only one.
Leak TL which decoder?
- Thread starter Linnovice
- Start date
Relived that I'm not the only one.
Arkless Electronics
Trade: Amp design and repairs.
Indeed I have read it. I have also heard many TL's, worked on many, modded many and designed and built about half a dozen decoders of different type and we will have to differ on this one. At very best they sound similar to a decent modern tuner but with poor sensitivity and selectivity etc meaning that a very good aerial installation is needed to avoid background noise (including various spurii), and also multipath distortion, which is what most bugs me.
They were originally designed as a mono tuner (a job which they do well) and even all the mods they did to increase RF gain and IF and discriminator bandwidth were not really enough to give it wide enough bandwidth and decent group delay performance for optimum stereo performance.
A really fettled one with proper alignment and a good external decoder and used with a multi element roof aerial properly installed for the stations of interest will in fact just beat a Stereofetic on sound quality and just about, "on a good day with a following wind" equal something like a typical Creek or Sugden tuner BUT everything needs to be bang on for this (and a big aerial well fitted!).
In most cases, in practice, a Stereofetic will win the day. Just not worth the hassle and money IMHO
A McIntosh MR67 and now we're talking! Prob best tuner I've heard.
After some deliberation I've decided not to update the decoder on my TL. I'm not happy with the sound quality as it is and, going by the comments that have been made, I think my efforts of makeing one from a kit may well be a waste of time. I expect eventually I will sell it on to someone who has the inclination and skill to make the amendments. I'll keep my Stereofetic as I am impressed with it. I've also just bought a Hitachi FT-5500 off of ebay. I look forward to receiving that later in the week.
Thank you all for your input and suggestions, they were not a waste of time and made valuable lessons for me. I'm sure I will be back with others, tuners facinate me, more so than the programmes sometimes.
Thank you all for your input and suggestions, they were not a waste of time and made valuable lessons for me. I'm sure I will be back with others, tuners facinate me, more so than the programmes sometimes.
As Jez said in an earlier post, the Troughline needs a good aerial to get the best from it. This is very true, but then again this is true to get the best from any tuner. The Troughline does not have the best sensitivity hence why you need a good aerial. If you haven't got a good aerial then you are wasting your time with a Troughline, and maybe a lot of other tuners too...
Big John
pfm Member
No aerials are allowed on the outside of our flats. I have a John Linsley Hood designed Quad FM aerial that I made from 1mm thick mild steel sheet it is very large. After building into the loft my son fitted it in the eaves in a space created for it; it has 25m of WF100 cable with a BNC connection to the leak. unlike my previous Antiference 5 element aerial the John Linsley Hood quad aerial allows full limiting ie the EM84 "magic eye" top and bottom virtually touch, good signal is vital with a Troughline as stated above.
Arkless Electronics
Trade: Amp design and repairs.
I made one of those as well! I'm thinking it was an article in Hi Fi News but not certain.
There are a couple for sale in Germany at the moment, around £800. Rather nice simple, no nonsense design if that is important to anyone.
Best tuner, across the board, or best tuner with valves?
Arkless Electronics
Trade: Amp design and repairs.
I believe that is cheap for one of those...
Best tuner full stop. Yes it is valved but I doubt that has much to do with it. Various 70's and 80's Japanese super tuners may well be better still.
Arkless Electronics
Trade: Amp design and repairs.
Not by the time it lands in the UK.......
Not since Jan 1st no!
Have to agree there.
I have a mono and stereo version. Stereo version needs fixing. The mono version listening to an orchestra via bbc R4 is like being in the venue. No harshness whatsoever from the string section etc.
The best tuner McIntosh made was the MR71. The best audio tuner ever made was the Marantz 10B. The best tuner I ever heard was a 1950s Rohde & Schwarz broadcast monitoring tuner. It was huge and weighed about 50kgs. I've heard no better but it was mono, but most would not know, or care as the sound was so good. I also owned a Nems-Clarke and a Watkins Johnson, both broadcast monitor tuners. To make these today would probably cost half a million euros each...
davidsrsb
pfm Member
Stereo always has fairly high distortion levels, it comes from group delay imperfections and the high frequencies used for the L-R signal.
Pressing the tuner mono button should get rid of most of this
George J
Herefordshire member
I have owned three Trough-Lines. At one time nearly ten years ago I had two at once. Both were the last mono variant which had an RCA socket to output to a separate decoder. I never bothered, and neither of them were in the best health. I had minimal repairs done on the better one and it could be rather good, but it would drift after a while, which I hated. With AFC engaged it was solid, but seemed to loose something of the quality when perfectly tuned manually.
I used that for several years.
Two years ago I decided to get VHF going again as I have a really nice signal from Sutton Coldfield. I bought a first variant mono with the short tuning range of 88-100Mc/s. I only need it to tune to 90.5 and 92.7 for R3 and R4.
This was fully refurbished, and I find it the most compelling source component I have ever used. Of course my replay is probably highly unusual in that my VHF/FM radio feeds [using its own variable volume output] directly to a single Quad mono valve ampler and then to a single ESL. Both the tuner and speaker were made in 1957.
A very fine 1950s radio set. Is it as technically fine as others made since? Probably not, even certainly not ...
But that does not concern me. This veteran radio set has given me more pleasure on live concerts on R3 than any other replay in my life. It is good enough. Also I find stereo is horrible. Give me well balanced mono and I am just drawn into the music ... I cannot ask for more ...
Best wishes from George
davidsrsb
pfm Member
Knowing how MC1310 and similar decoders work, not every third party decoder will be equal. These chips are fussy about layout to minimize PLL jitter, sensitivity and setup.
They also have options for group delay correction, which affects distortion.
I have seen plenty of single sided PCB designs, that are very poor from the layout point of view
They also have options for group delay correction, which affects distortion.
I have seen plenty of single sided PCB designs, that are very poor from the layout point of view
Arkless Electronics
Trade: Amp design and repairs.
They are not fussy about layout (very few things for which this is claimed actually are!). Any old layout will do just fine. Set up (just setting one preset for oscillator frequency) is not critical. Optionally, an adjustable phase lead network can be included at the input to allow optimisation of separation. There is no option for group delay correction as such.
I've found the HA11223 one of the best decoders as it has low distortion and pilot tone cancellation. I used this in an FM tuner I designed for Alchemist Products.
davidsrsb
pfm Member
Maybe I have access to too much test equipment and have spent a lot of my career with VCOs and PLLs. They do improve with care, how far is overkill is debatable.
The lead network is what I meant, it has to match the tuner group delay.
Agreed on that, much better than the MC1310. Pilot tone cancellation means no nasty notch filter needed