And nothing feels better than using something that you've had some part in creating.
is it art or is it science?
or both.
BTW just to add a little ''controversy'' into the mix and aimed at all users.
Has anyone tried having a play with different ''brand'' caps for C5 (10UF) input cap?
I started out using some Nichicon muse ES types and they
sounded pretty good but compared to the Black Gate BP that replaced them a
little less clear to my ears and in my set up. The Black Gate BP sounds very
clear but those are unobtainium except for the mostly fake ones on eBay. Zen
mods Silmic bypassed with a small film also looks interesting but I've not
tried it so can't say for sure.
ATM that's the only cap directly in the signal path (the rest is all DC coupled) so I wanted to make that a good one. some people believe that caps all sound the same and I accept hat view as a valid point to their ears and in their set up.
But my experience tells me something different.
Of course the amp topology has a more profound affect on the sound IMHO but I like to try a few small things.
And nothing feels better than using something that you've had some part in creating.
is it art or is it science?
Yes it does. And I took only the ready made board option. Presumably even more so if one has slaved over the boards themselves. I can only guess at what the designer himself must experience when listening to his own creation!
I think that in general "creation" is a wider concept than art or science, though it may encompass either or both. Probably a lengthy discussion on the meaning of each term is required! But let's not do that... (That's a rather weak answer! :-D )
Even with the ready made option there is still plenty to do to get the amp up and running so it still counts as DIY.
I did notice your question on pre-amps and I do have a take
on that.
IMHO preamps do offer the usual ability to switch inputs and
adjust the volume
But to my ears they also give an opportunity to further ‘’tune’’
the sound. I have a digital and analogue set up but with digital I still prefer
to adjust the volume in the analogue domain for best quality sound.
It’s just a personal preference thing but With the SECA I also
prefer a pre with a little gain which to my ears gives a slightly more in room
sound.
But that’s just my subjective take and others will have
equally valid opinions.
I have errrr well let me see.
Glass house TVC, DCB1, B1, DACT in a box passives and apha20
Jfet complimentary pair, Pass ba-3 (I like Jfet) Avondale 821A (tweaked a
little) and to my ears the Actives give a little more drive and drama to the
sound.
The through hole Pre that Colin posted looks superb and
maybe a nice way to find out for yourself would be to build that next now that
your OCD is fully kicked in.
Even with the ready made option there is still plenty to do to get the amp up and running so it still counts as DIY.
I did notice your question on pre-amps and I do have a take
on that.
IMHO preamps do offer the usual ability to switch inputs and
adjust the volume
But to my ears they also give an opportunity to further ‘’tune’’
the sound. I have a digital and analogue set up but with digital I still prefer
to adjust the volume in the analogue domain for best quality sound.
It’s just a personal preference thing but With the SECA I also
prefer a pre with a little gain which to my ears gives a slightly more in room
sound.
But that’s just my subjective take and others will have
equally valid opinions.
I have errrr well let me see.
Glass house TVC, DCB1, B1, DACT in a box passives and apha20
Jfet complimentary pair, Pass ba-3 (I like Jfet) Avondale 821A (tweaked a
little) and to my ears the Actives give a little more drive and drama to the
sound.
The through hole Pre that Colin posted looks superb and
maybe a nice way to find out for yourself would be to build that next now that
your OCD is fully kicked in.
Thanks for your input there. I suppose the whole pre- thing is something I'll just have to listen to... I've not had analogue active preamping for 10 years, so it would be interesting to go back to it with the new setup I now have.
Even with the ready made option there is still plenty to do to get the amp up and running so it still counts as DIY.
I did notice your question on pre-amps and I do have a take
on that.
IMHO preamps do offer the usual ability to switch inputs and
adjust the volume
But to my ears they also give an opportunity to further ‘’tune’’
the sound. I have a digital and analogue set up but with digital I still prefer
to adjust the volume in the analogue domain for best quality sound.
It’s just a personal preference thing but With the SECA I also
prefer a pre with a little gain which to my ears gives a slightly more in room
sound.
But that’s just my subjective take and others will have
equally valid opinions.
I have errrr well let me see.
Glass house TVC, DCB1, B1, DACT in a box passives and apha20
Jfet complimentary pair, Pass ba-3 (I like Jfet) Avondale 821A (tweaked a
little) and to my ears the Actives give a little more drive and drama to the
sound.
The through hole Pre that Colin posted looks superb and
maybe a nice way to find out for yourself would be to build that next now that
your OCD is fully kicked in.
Thanks for your input there. I suppose the whole pre- thing is something I'll just have to listen to... I've not had analogue active preamping for 10 years, so it would be interesting to go back to it with the new setup I now have.
I was completely in the Passive/no-pre camp since the mid-80s, but the Listen makes the SECAs sound significantly better, so I'd recommend you try (preferably) one of Colin's pres with yours.
Try 10uF Polycarb caps, sound amazing but not cheap min voltage 63V.
TBH I figured that the litic was used on the IP for a sound reason so I've tried to stick with those.
but I think that Keith uses a polyprop on the IP of his SECA and likes the sound. The BG to my ears gets pretty close to a good film but I must try a few more options.
I've been cap rolling for quite a few years now and built up quite a collection and a PIO would be appealing but a monster size wise.
I do still like the idea of the bypassed Silmic so may try those next but I have some Mundorf MKP also but worry about the sound balance a little with those.
I may try those before the lid goes on but I'm more than happy as is.
BTW even though the passives I
have to my ears sound detailed with the SECA (I'm reluctant to use the word
transparent because well who really knows what that is?) but the actives, even
the pocket rocket Alpha20 sounds more satisfying and in the room without the
detail drop.
Shall we say more musically satisfying?
I suspect a SECA pre would bring more of the same which can
only be a good thing.
Yesterday I noticed that the left channel is a bit lethargic getting going. From cold, it seems to take 5 seconds to come on compared to the right (the LED on the left side illuimates immediately). After this it appears to behave normally (as far as I can tell). Once warmed up the lag reduces to a split second if I flick it off and on again, but is still there. Any thoughts...? :-?
Yesterday I noticed that the left channel is a bit lethargic getting going. From cold, it seems to take 5 seconds to come on compared to the right (the LED on the left side illuimates immediately). After this it appears to behave normally (as far as I can tell). Once warmed up the lag reduces to a split second if I flick it off and on again, but is still there. Any thoughts...? :-?
Ben it is only tolerance in timing caps so not a problem, Most caps are Value +20% -5% and change over time.
Its worth fitting a thermal trip on the transformer primary.
I used 70 degrees c on mine.
Paul it is also a good idea to fit a snubber around the thermal switch as they are normally used on no reactive load like transformers so the peak backing emf will kill the contacts, a simple R+C lets say 100R 2W + 100nF X Class 275VAC will fix most of the problems caused by the backing emf. These fit in series across the thermal switch, please do it with the mains disconnected, it take weeks for the hearing to come back after a electric shock, and I have had a few. Got "T" Shirt and Undies now. 8-X
Yesterday I noticed that the left channel is a bit lethargic getting going. From cold, it seems to take 5 seconds to come on compared to the right (the LED on the left side illuimates immediately). After this it appears to behave normally (as far as I can tell). Once warmed up the lag reduces to a split second if I flick it off and on again, but is still there. Any thoughts...? :-?
Ben it is only tolerance in timing caps so not a problem, Most caps are Value +20% -5% and change over time.
Lovely answer. Thank you Colin. :-)
And how very analogue... ;-)
my build is some way off of being photogenic but once I summon the courage to tackle the metal work I'll post some snaps.
metal work is my least favourite part and it's going stretch my limited abilities ( a five year old ) to the limit.
pictures will follow.
Yeah. I know what you mean. I felt a bit like a toddler playing with his Fisher Price work bench when I was hacking away at the plates of my case. I was very glad of wide fitting cable grommets and sockets that covered a multitude of sins! Anyway, looking forward to the portraits you take when ready.
As Shaun mentioned I used a polypropylene capacitor on the inputs of my amp after being initially dissatisfied with the electrolytics which seemed to impart an edginess to the sound. The cap that I used was a Vishay MKP1839 10uf 160V which is mounted off board as it is quite large and the input resistor was soldered at the rca input.
As Shaun mentioned I used a polypropylene capacitor on the inputs of my amp after being initially dissatisfied with the electrolytic which seemed to impart an edginess to the sound. The cap that I used was a Vishay MKP1839 10uf 160V which is mounted off board as it is quite large and the input resistor was soldered at the rca input.
As Shaun mentioned I used a polypropylene capacitor on the inputs of my amp after being initially dissatisfied with the electrolytics which seemed to impart an edginess to the sound. The cap that I used was a Vishay MKP1839 10uf 160V which is mounted off board as it is quite large and the input resistor was soldered at the rca input.
Hi Keith
You also used Silmic bypassed with a small film for your BA 3 build if I remember rightly.
I was thinking of trying the same or the SECA at some point.
Hi Col; Shaun; with the polyprop on the Seca input the sound smoothed out especially in the upper mids and top end whilst loosing nothing in the bottom end drive and dynamics.
The BA3 pre output I replaced the bypassed Silmic with a CrarityCap esa and to be honest the difference was marginal. Should have saved my money.
Afternoon all. I've finally got my amp and PSU boards mounted and I'm going to start wiring it all up shortly. Before I do this I have some questions:
In some of the SECA builds, I can see a wire running from position PR2 on the amp board to a grounding point on the aluminium strip onto which the FET's are mounted. Can I ask what this is for please? Is it essential?
I plan to use hookup wire to connect the RCA plug to the amp, but there isn't an obvious mounting point for the signal wire - can I just solder the wire to the central circle?
Initially I'd like to get 10 watts from my amp.
What do I need to adjust and measure with a meter to ensure:
a) I'm getting 10 watts and that
b) my build won't jettison my speaker drivers when I turn the amp on for the first time?
I know for example that with my DAC I had to dial out a small amount of DC via a pot - does the same apply here?
Apologies if some of these points have already been covered.....I'm trawling this thread now to see if I've missed anything else.
@Brumjam the wires from near PR2 are the leads from a thermistor which is attached to one of the output mosfet fixing screws and helps control the bias current with temperature. I'm sure Col will jump in if I've got that wrong.
Not 100% sure how to ensure exactly 10 watts.
DC offset is set by turning PR1 clockwise when things have warmed up to obtain a zero reading or as near as you can get. I ended up with a couple of mv but it fluctuates a little with temp.
@Brumjam the wires from near PR2 are the leads from a thermistor which is attached to one of the output mosfet fixing screws and helps control the bias current with temperature. I'm sure Col will jump in if I've got that wrong.
Not 100% sure how to ensure exactly 10 watts.
DC offset is set by turning PR1 clockwise when things have warmed up to obtain a zero reading or as near as you can get. I ended up with a couple of mv but it fluctuates a little with temp.
Thanks both. Having read back I can see that I need 200mv at R11 and then when this has stabilised adjust the DC offset if any is present. Is there anything else or am I good to attach my test speakers?
How many watts are my speakers seeing with R11 set at 200mv?
Switched my amp on (one channel only is connected at moment). Green light lit up on amp board, but I'm not seeing any reading on my meter across the 01R closest to TIP142 when I adjust the current. Can someone tell me what voltages I should be seeing being fed from the PSU board please? I'd like to rule out any errors I might have made on the PSU board first.
Comments
I started out using some Nichicon muse ES types and they sounded pretty good but compared to the Black Gate BP that replaced them a little less clear to my ears and in my set up. The Black Gate BP sounds very clear but those are unobtainium except for the mostly fake ones on eBay. Zen mods Silmic bypassed with a small film also looks interesting but I've not tried it so can't say for sure.
I think that in general "creation" is a wider concept than art or science, though it may encompass either or both. Probably a lengthy discussion on the meaning of each term is required! But let's not do that... (That's a rather weak answer! :-D )
I'm afraid I can't comment on the caps issue!
I did notice your question on pre-amps and I do have a take on that.
IMHO preamps do offer the usual ability to switch inputs and adjust the volume
But to my ears they also give an opportunity to further ‘’tune’’ the sound. I have a digital and analogue set up but with digital I still prefer to adjust the volume in the analogue domain for best quality sound.
It’s just a personal preference thing but With the SECA I also prefer a pre with a little gain which to my ears gives a slightly more in room sound.
But that’s just my subjective take and others will have equally valid opinions.
I have errrr well let me see.
Glass house TVC, DCB1, B1, DACT in a box passives and apha20 Jfet complimentary pair, Pass ba-3 (I like Jfet) Avondale 821A (tweaked a little) and to my ears the Actives give a little more drive and drama to the sound.
The through hole Pre that Colin posted looks superb and maybe a nice way to find out for yourself would be to build that next now that your OCD is fully kicked in.
Thanks for your input there.
I suppose the whole pre- thing is something I'll just have to listen to...
I've not had analogue active preamping for 10 years, so it would be interesting to go back to it with the new setup I now have.
Cheers ears
Interesting
I‘ve been having a little play with the bias setting today and set up as follows:
Ambient room temp 25deg give or take a foot.
Bias 2.5A
Sink temp 60deg
So 35deg above ambient.
Then I switched the fan on blowing non-stop and the settings where as follows after allowing the temp to stabilise.
Ambient room temp 25eg
The bias slowly went up to 2.75A
Heat sink temp 42deg
17deg above ambient.
So even going up to 2.5 with the fans I can afford ambient temp of 40deg and still be within safe operating conditions.
The fans are way cheaper than buying a bigger heatsink and do a good job of cheating the specs up a little for better a damping factor.
And if the fans fail at any point then the bias goes down and still keep things reasonably safe so long as the ambient is not greater than 30deg.
The sound since using the fans has grown a bigger pair bass wise and has grown a little in size to my ears and in my set up.
Money well spent.
Any thoughts...?
:-?
How / where have you positioned the fans? Piccies...?
Anyway, looking forward to the portraits you take when ready.
Nude portraits are the pinacle of artistic work.
Snaps of your amp in the buff please.
The cap that I used was a Vishay MKP1839 10uf 160V which is mounted off board as it is quite large and the input resistor was soldered at the rca input.
I used the Wima MKS2 10uf 50v..........stuck down with a blob of rtv.
Only a polyester though, so probably not quite as good as polycarbonate or Polypropylene
The BA3 pre output I replaced the bypassed Silmic with a CrarityCap esa and to be honest the difference was marginal. Should have saved my money.
Not 100% sure how to ensure exactly 10 watts.
DC offset is set by turning PR1 clockwise when things have warmed up to obtain a zero reading or as near as you can get. I ended up with a couple of mv but it fluctuates a little with temp.
How many watts are my speakers seeing with R11 set at 200mv?