You admit something which an astonishing number of people deny. They might be annoyed at you for failing to secure the feline in the receptacle; some may even try to claim that you are mistaken in your analysis of why you prefer a slightly distorting CF.wa2ise said:
I guess one difference between you and them is that you actually understand electronics. 73's G8HQP (DF96)
Listening test
A friend came round last night and enquired why I bother with using a buffer. So we did a listening test then bypassed the CD3 and I was shame faced as there was little or no difference
He laughed, I did not........
I explained that it 'use' to make a difference....
Ok, Bought new 2 years ago and replaced the caps but kept the original valves. Have they gone off so soon ?
A friend came round last night and enquired why I bother with using a buffer. So we did a listening test then bypassed the CD3 and I was shame faced as there was little or no difference
He laughed, I did not........I explained that it 'use' to make a difference....
Ok, Bought new 2 years ago and replaced the caps but kept the original valves. Have they gone off so soon ?
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Clearly in some impedance situations, the Yaqin CD3 can provide impedance improvement.
A 6sn7 has a gm ~ 2800 umhos, but the CD3 has 2 triodes in parallel, so I think Zout ~ 180 ohms.
Adding the CD3 to my CD player, makes a dramatic improvement when driving an F5 amplifier.
The F5 has very little capacitance in the front end.
However, the CD3 does not have the poop to drive my Musical Fidelity A3.2cr power amp.
Rin = 47K for this amp, but I don't know what Cin is like.
Many tech's will say a preamp to power amp Zout / Zin ratio = 0.1 is OK.
However, if you look at actual ratios used by Sim Audio, Musical Fidelity and tube equipment
the preamp to power amp Zout / Zin ratio is in the order of 0.001.
.
A 6sn7 has a gm ~ 2800 umhos, but the CD3 has 2 triodes in parallel, so I think Zout ~ 180 ohms.
Adding the CD3 to my CD player, makes a dramatic improvement when driving an F5 amplifier.
The F5 has very little capacitance in the front end.
However, the CD3 does not have the poop to drive my Musical Fidelity A3.2cr power amp.
Rin = 47K for this amp, but I don't know what Cin is like.
Many tech's will say a preamp to power amp Zout / Zin ratio = 0.1 is OK.
However, if you look at actual ratios used by Sim Audio, Musical Fidelity and tube equipment
the preamp to power amp Zout / Zin ratio is in the order of 0.001.
.
There is still something wrong here.
Not only has my CD3 stopped making a difference there is also a lot of noise / background hash coming through the speakers.
Any ideas ? It's unusable like this. Have visually looked at the circuit with nothing of note. Could it be the valves ? I don't have any others to compare with.
Regards
Not only has my CD3 stopped making a difference there is also a lot of noise / background hash coming through the speakers.
Any ideas ? It's unusable like this. Have visually looked at the circuit with nothing of note. Could it be the valves ? I don't have any others to compare with.
Regards
You see just about any one who prototypes FR-4 boards
uses rubbing alcohol in a bottle and a Q tip to remove the flux.
I wouldn't suggest spraying anything into your buffer.
Forgive me for clarifying your statement, but it may be confusing for beginners.
Passive L C & R components create linear impedances.
I think its a transistor's parasitic capacitances that are non linear.
To put in simpler terms, the CD3 buffer needs to able to effectively charge and discharge the RC in the front end of the amp its trying to drive.
If it doesn't supply enough poop, the sound will be thin and lifeless.
A CD player with volume control ==> modded CD3 with CV-181 tubes ==> F5 Amp sounds glorious.
Tubes driving an F5 sounds very good.
However, I seriously doubt the CD3 could drive an Aleph 5 with IRF9610 mosfet's on the input.
I use a DAC ===> CD3 buffer ===> Roksan Caspian integrated with good results.
The output coupling cap I have in the in the CD3 is a Mundorf M-Cap supreme,
these have a just the right amount of resolution to help filter out "digital glare" coming out of the DAC.
.
No components are perfectly linear, but most are sufficiently linear. Active devices are likely to be the most non-linear, and not just their capacitances. The input current to the base of a BJT or the grid of a valve may be small but it can be very non-linear. That is what I was talking about. Non-linear parasitic capacitances can have an effect at higher frequenices too.Uunderhill said:
Everyone measures voltage non-linearity (that is, those who measure anything). Fewer people measure impedance non-linearity. One way to get a rough idea is to deliberately drive an input from a high impedance and see how much it degrades linearity. If it makes no difference then the input has a linear impedance, however linear or non-linear the device/unit itself is. If you have linear impedances then you probably don't need a buffer.
BB,
Make sure your Yaqin CD3 has been unplugged for at least 10 minutes before taking a measurement.
Remove the tubes when they have cooled down.
Stay clear of the 180uF 250V caps on the right which can hold a charge.
Try setting the multimeter to either 200K or 20M ohms.
With one lead, make good contact with a solder island that the output coupling caps are connected to.
With the other lead, make good contact with an adjacent solder island.
See if there is any reading.
Try this in a number of locations.
Now clean the flux off with a rubbing alcohol and a Q tip.
See if there is any difference in the reading.
Make sure your Yaqin CD3 has been unplugged for at least 10 minutes before taking a measurement.
Remove the tubes when they have cooled down.
Stay clear of the 180uF 250V caps on the right which can hold a charge.
Try setting the multimeter to either 200K or 20M ohms.
With one lead, make good contact with a solder island that the output coupling caps are connected to.
With the other lead, make good contact with an adjacent solder island.
See if there is any reading.
Try this in a number of locations.
Now clean the flux off with a rubbing alcohol and a Q tip.
See if there is any difference in the reading.
Many thanks Uunderhill, did as instructed and no readings from the caps. So today me and a friend pulled my system apart and found the culprit lurking in my music PC in the form of an earthing fault. Rather strange and confusing at the same time as the noise being there sometimes and not others - weird. USB really bad, so connected via laptop and its gone. Back to the PC and the only way to avoid it is via XLR from the DAC to amp - Ummm strange. But means can not put back the CD3 into the chain.
Checked PC mobo wiring and changed mains cables. So what's left, can only be PC's power supply gone faulty I wonder ?
Checked PC mobo wiring and changed mains cables. So what's left, can only be PC's power supply gone faulty I wonder ?
YAQIN SD-CD3
Hi anyone knows whether YAQIN SD-CD3 will accept Mullard ECC88? ( without modification) or should I use another sockets to inert the tubes?
Grepin CV181 is festive looking
Think I'll begin by swapping the blue caps with Dayton 0.47uf 400V caps that I have. These are cheap and pretty good sounding. Any idea if swapping 0.47uF for the 0.22uF pair is a no-no? If these are in the signal path I would think there's no harm.
Hi anyone knows whether YAQIN SD-CD3 will accept Mullard ECC88? ( without modification) or should I use another sockets to inert the tubes?
Hi, it was pleasure to read your posts, your approach remind myself, to dig in till it gets clearer of what is all about or a part of it about. I'm not a great expert to PCB boards, however I have some understanding. I liked the internal parts of this Tube Buffer for the model "YAQIN CD2-6J1"
YAQIN CD2 6J1 Tube Signal Upgrade CD Buffer Processor for CD Player | eBay
Its internal parts are very straight forward and no PCB board in there! To me its better. Can you guys have a look under the hood of it and give your opinion, may be its better to go for this model instead of "YAQIN SD-CD3" seems as simple design, may be the rule applies here "Simple is better"
They are actually somewhat similar, you just get to roll different tubes, HAH.
I own the CD2 and use Mullard tubes CV series CV4010? In the CD2 it's pretty easy to add bypassing caps, a photo-flash cap in the PSU, faster bridge-rectifier diodes. The CD3, Man, you could mod that to take everything form the stock RUssian tubes to old USA 6F8G [with adapter] to smaller tubes...[adapter socket again], and one I'd love to try if I owned a CD3 would be the 7193 tube! 2 top-terminal caps each required. The CD2 is a bit harder to dig the in and out caps out of, though I just added bypassing to them and called it good. I tend to look beyond as well -- if the next stage [say a preamp] has input caps, those could be shorted [on purpose]. Why spend $50 on new caps in CD3 only to feed that onwards to some NP Electrolytics? Or polars not properly DC biased sometimes...
Once I already own Mullard ECC88 that cost me a lot of money, would you think I have a chance to use them in YAQIN CD2-6J1 Tube buffer? Should I use a some sort of adapter, or just do some soldering joins underneath (below, on the existing socket)?
Here are the pictures of Mullard ECC88 https://plus.google.com/photos/103965235820975061444/albums/5842899239915415713
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ECC88
Yes, wrong number of pins, CD2 or CD3 [either] would require adapters 9P? female to rewired 7P in the CD2? Something that might be much easier to try is 6n16b-v tubes since they have the wire leads {with sleeve tubing added}, or you could tack tube-pins on the the wires and stuff in socket with needle-nosed pliers...or tack leads to 14Ga house wire "pins"? 16Ga? Parallel the two triodes in each tube -- same way they do in CD3
Yes, wrong number of pins, CD2 or CD3 [either] would require adapters 9P? female to rewired 7P in the CD2? Something that might be much easier to try is 6n16b-v tubes since they have the wire leads {with sleeve tubing added}, or you could tack tube-pins on the the wires and stuff in socket with needle-nosed pliers...or tack leads to 14Ga house wire "pins"? 16Ga? Parallel the two triodes in each tube -- same way they do in CD3