Poundland 45

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Cressy Snr
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#106 Re: Poundland 45

Post by Cressy Snr »

Decided I need to get a bit of practice in with solid state stuff, so on a bit of perf board, I built my own DC heater supply for the ECC88, rather than relying on bought in modules and learning nothing. I'd put the cascode CCS together from a Morgan Jones diagram and found success, so I simply found another application note for the LM317, and built something along those lines. OK it's not exactly a state of the art supply but, I reckon it's perfectly adequate for an IDH driver valve. A phono stage might be a different story but I'll use something better when I get around to building that.

I can't say I can hear any difference whatsoever between the fancy DIYHS DC module and this thing I made up, so I'm quite pleased at the outcome:
DCheaterreg.png
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Below, the DC heater supply can be seen at the bottom right hand side of the chassis, which now looks remarkably tidy considering the small amount of available space inside, though I say so myself. I'm chuffed to bits with how this project has turned out. Many thanks to the donators of the quality parts that made this come to fruition. You know who you are.
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#107 Re: Poundland 45

Post by Mike H »

:thumbleft:
 
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#108 Re: Poundland 45

Post by Cressy Snr »

So all that solid state gubbins has lasted about a month all told.
Yes, it was very nice and all that, couldn't fault it really, but over the past week or so, it started to get on my wick. It had all become a bit too analytical in terms of its presentation. There was dynamics a-plenty, detail a-plenty, separation, nice treble, deep bass - all those hi-fi qualities we spend our lives trying to get at. Trouble is, the music went AWOL.

What I mean by that is that the sense of performance; that of human beings playing music and interacting with one another, being able to feel that there was a singer, pianist, saxophonist, trumpeter, guitarist, organist in the room, had become somewhat diminished. I was listening to recordings on an intellectual level rather than on a level where the music was communicating with me. The tonal colours had become washed out and a lack of vibrancy seemed to be the way it was I had gained a lot, but lost something more important.

I've spent the whole of today, removing all the solid state circuitry on the front end and reverting to simple AC heaters and non regulation of the HT.
I found two Hammond 266M2 filament transformers and now the 45s are on individual transformers, rather than on a winding each off a single filament transformer.

A 12V transformer rescued from a halogen light fitting was pressed into service to feed the ECC81 front end, which had earlier replaced the ECC88. This had given the presentation a teensy bit of second harmonic love, when the the solid state stuff was in situ. It was the first attempt to inject a bit of life into the situation, prior to today's adventures. I didn't post about that, because although it went a small way towards bringing things back to life, it didn't go anywhere near far enough.
With the AC everything and the ECC81 running the show at the front end of the amp, I'm back to where I began this love affair with 45s.
I've learned a lot with the transistor bits and I think the CCS feeding the VR tube shunt regs worked really well. The DC on the front end heaters worked too, but in the end, something went missing along the way. Again we have a case of 'you can't just....' As with everything else to do with SETs, there is a great deal more to things than meets the eye.

45s seem to prefer things to be simple and straightforward ' I'm glad I did the solid state and the DC. It was a useful learning exercise. In the case of my amp and my limited experience of this sort of thing, in the end it just wasn't for me.

I've kept the SS rectification, but I've added a bit of series resistance:
1) to pull down the overall HT level a bit and
2) to give some of the sonic flavour of a valve rectifier (Blencowe)

Luckily, I've been able to get the sound back to where it was. I’ve not normally been as successful regaining ground lost in that manner. I'm thankful :)
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Nick
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#109 Re: Poundland 45

Post by Nick »

I just have to say, if it was me I would look to see if I could fix it instead of going around the wheel again. For example:
I can't say I can hear any difference whatsoever between the fancy DIYHS DC module and this thing I made up, so I'm quite pleased at the outcome:
I would have tried that again to check if you still could not tell any difference,

Also, maybe consider the source, maybe all that is happening is that you are hearing faults elsewhere.

None of the above may be correct, but I would have tried.
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#110 Re: Poundland 45

Post by Cressy Snr »

Hi Nick,
Yes it would have been perhaps more appropriate to have investigated the issue further, rather than taking it apart and ‘downgrading’ things.
If it had turned out the amp was revealing faults further up the line then I would have been stuck between a rock and a hard place, as I don’t have the funds available to improve the sources. It’s an expensive rabbit hole I don’t want to go down.
I probably overstepped the limit of what this budget DIY system is capable of. I guess I’ll never know what might have been with better sources.
In its present format, It certainly gives a good portrayal of music, I’ve not had anything better in almost fifty years of being into hi-fi, which isn’t bad going really.
Last edited by Cressy Snr on Thu Nov 11, 2021 10:56 pm, edited 1 time in total.
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#111 Re: Poundland 45

Post by izzy wizzy »

I've come to realise we all focus on different stuff and in different ways. I've come to a not too dissimilar recipe to get the sound I like and yet it's PP or differential.

To date, (always ready to be proved wrong), the only SS stuff that's stayed in are the Lehanne DHT regs. Maybe it takes a lot more work than I put in to get the SS bits right or how I like.

Nice work. Must be good to be back where you want. Now don't fiddle anymore before Owston ;)
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#112 Re: Poundland 45

Post by Nick »

It might be worth checking the thread that covered the work that Andrew and Mark put in to get the heater regs as they are now. It's was not a simple matter. Details are important. Small things matter.
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#113 Re: Poundland 45

Post by Ant »

Its strange this amp. i say strange, because the last time i heard it properly with all its ss bits in, about a week ago, i thought it was great. It was kind of similar my f5 in its presentation. Heard it yesterday, and it was great, but not like my f5. It seemed more 'free' if that makes sense, not so controlled. Analytical is a good way to describe how it was, very matter of fact for a valve amp. Now id describe it as flowing
Thing is, i like analytical. my system with practically the same tt, very similar speakers in terms of overall characteristics, leans that way. Simon commented that the arm ive been developing sounded analytical, and it does. Ive inadvertently made it that way.
Its just the bit in the middle that is different
Either systems characteristics are not something thats immediately apparrent, but both sound right to me
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Paul Barker
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#114 Re: Poundland 45

Post by Paul Barker »

Steve you’re similar to me; I would settle in now at the simple. You don’t have to develop a recreatable use of solid state filament supply. Let those who benefit from it and may have a bigger picture in mind that is consistent repeatable and does no harm to the sound.

The only place I’d be with youre design that differs from you is use choke input and valve rectified 100%. As a target.
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#115 Re: Poundland 45

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You don’t have to develop a recreatable use of solid state filament supply. Let those who benefit from it and may have a bigger picture in mind that is consistent repeatable and does no harm to the sound.
That was not the point I was making, but good attempt to frame it as you want. The work Mark and Andrew did was driven by sound quality, all the rest just happen. Though I would suggest repeatability is not a bad goal for a filament supply as you will normally use at least two. My point was that finesse and patience is needed.

My view is that there is a very thin line between "fluid" and "analytical" that has the best of both, but if you are wearing hob nail boots you don't notice it as you stomp from one side to the other.
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#116 Re: Poundland 45

Post by Paul Barker »

All You’re creations sound great Nick. But I know how much you’ve worked especially with Mark evaluating changes in Andrew’s modules. It’s no small task.

I’m more in the simpleton level, a passenger to these hard trying an adjustment and getting it 3rd party evaluated.
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#117 Re: Poundland 45

Post by Nick »

There is a thing in software. There is never time to do it right but always time to do it again.
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#118 Re: Poundland 45

Post by steve s »

Nick wrote: Fri Nov 12, 2021 12:59 pm There is a thing in software. There is never time to do it right but always time to do it again.
I like that.. nowadays unfortunately it seems to apply to alot of trades.

I must say Andrew's dc heater modules are the best, they are in all my dht output stages... so they must be !
But I still prefer simple-ish amplifiers.
I have done for years... but thats nothing new.
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#119 Re: Poundland 45

Post by Cressy Snr »

Complicate, disappear up my own arse, dismantle.
I’ve broken the cycle. You’ve no idea how happy that has made me.
If I want to do DC in future, then I’ll make use of Andrew’s modules. It’s a no-brainer.
The hard work has all been done, so reinventing the wheel is a bit silly.
I only wanted to learn a little bit about the ins/outs/perils of DC. Causing a problem was not the intention.
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#120 Re: Poundland 45

Post by Ant »

Cressy Snr wrote: Fri Nov 12, 2021 2:18 pm Complicate, disappear up my own arse, dismantle.
This is exactly why ive built 2 versions of the arm.
When I think ive come up with a better idea for it, ive dismantled the earlier version and built my 'better' version. Then compared it to the one i was trying to better

This is the only thing that has stopped me going round in circles, and having 2 decks that are practically the same and using the same cart has been important.

Id have never got it as far as i think i have without being able to go back to the control version, though its not viable to build 2 amps just for the sake of comparison.

Id have disappeared up my own arse and given up without the control version, i almost gave up on it when it had the acetal bearing housing and i couldnt work out why i didnt like it. It can be Very frustrating
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