Where I can delete some old posts? Did I say it sounds not so good? It sounds soooo good!
Propellerheads "Decksandrumsandrockandroll": just had a try at track 1: OMG!
I've found a flaw, highs are a bit harsh. Maybe too many LM4562? (in amp also...) or maybe normal without clock & regs? Maybe the sound of the amp?
Propellerheads "Decksandrumsandrockandroll": just had a try at track 1: OMG!
I've found a flaw, highs are a bit harsh. Maybe too many LM4562? (in amp also...) or maybe normal without clock & regs? Maybe the sound of the amp?
Malefoda said:
Hard to say. Try a different source with the amp, and interconnects. Harshness on the CD player can be helped with soft-recovery diodes and upgrade of the analog filtering - I don't remember what you've done. Cerafine electrolytics have a softer sound to me, or BGs can help. The LM4562 even broken in sounds clear. I would borrow another source to see if its the amp.
Hi Simon,
this sounds like you have the chassis safety earth connected to the audio ground. Am I interpreting that correctly?
SimontY said:
Hey Simon!
Nice pictures, looks very neat. Nice connector job! I guess i'm falling behind, since my players still use the internal PSU 😀. Maybe i'm going to make one with tubes
.Ray
AndrewT said:
It's as discussed previously. To recap: the CD and CD chassis are connected to safety earth, CD has star ground point.
The PS is "disconnected" from safety earth via 8.2/22nF but the chassis is directly connected for safety and shielding. PS also has a star ground point.
The two stars are connected via the binding post on CD end and hard wired at PS end (soon to add isolated binding post, I didn't want to drill at 12.30am).
I hope it's clear now. It's not such a simple machine anymore! lol
Simon
rowemeister said:
It sure would be
Yeh, thanks mate, I'm really pleased with how it's working out.
Next is another transformer and I will separate digital and analogue (one tx. for each).
I did originally consider two sets of 8-way DINs, one for ana and one for dig, but now that the earth is separate 8 pins is going to go a long way! Three used so far: clock, divider, 5v board. The 5v will become two. Next will be two psus for the all-important servo I think. That's only 6 in total!
6h5c said:Hey Simon!
Nice pictures, looks very neat. Nice connector job! I guess i'm falling behind, since my players still use the internal PSU 😀. Maybe i'm going to make one with tubes
Ray
Thanks Ray. The neatness is questionable in places, nothing like your immaculate work.
Well, you may not have an external psu, but I do not have your excellent output stage built yet. It's pricey to make using only the best parts but I will get onto it as soon as time and money become available! I of course heard it in Brent's and I want!
Simon
Ray - why does your passive filter + FET output stage need a coupling cap on the end? Forgive my ignorance!
Also, I have four HA5033 buffers to hand (same as OPA633... I think) they only generate about 15mV of offset.
I'm wondering if I could attach these to the end of some passive filter.
HA5033
Also, I have four HA5033 buffers to hand (same as OPA633... I think) they only generate about 15mV of offset.
I'm wondering if I could attach these to the end of some passive filter.
HA5033
Glenn2 said:
Off the top of my head I think there is 7V dc on the output.
If people can't remember mine has the BG ac types fitted.
An externally hosted image should be here but it was not working when we last tested it.
Brent
SimontY said:
Thanks Simon, i'm honoured...😎
Glenn2 said:
Brent is right, the output stage is single-ended and there's an offset present on the emitter of the last transistor (or FET). So decoupling (with a good cap obviously) is mandatory. Personally I wouldn't use an integrated buffer. The discrete output stage is by far less complicated compared to the internals of the 5033. I like to keep things simple, less is better. Besides, you don't need the extra speed and slew-rate of a video amp after a passive filter network. The figures in the datasheet like distortion and PSRR are not very impressive. But it won't hurt to try, I never did any experiments with these things and maybe it sounds quite good?
Be aware that the 15mV offset figure only indicates the offset generated by the device itself. For example if you offer 1,000V DC at the input you'll get 1,015V at the output 😀. You still have to get rid of the DC offset generated by the DAC.
Regards,
Ray