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Thank you for suggestions. Some are rare that finding one may be an issue & like a kid I want to play. Intregrated is easier for me as matching preamps can be difficult to find.
BTW- The beautiful Sansui AU-X701 was distroyed by FedEX. It was speared by a sharp object into the chassis & ripped thru the metal chassis. Real cute FedEx.
I find the Yamaha CA-1010 highly rated and available so I will find one. The Sony TA-1130 is a good suggestion, but rare. Is the TA-1150 the same but a different power rating of ??? I like smooth, but crystal clear & dynamic audio. Creamy or warm or typical run of the mill PP vintage amp tube distortion is no fun for me.
Philips? Not much for sale & overpriced IMO. What else should I seek? Marantz & McIntosh are of no interest right now. I owned a Marantz 2216 and the internal amp sonics was sorely lacking details & open dynamics.
Follow Ups:
Didn't the A1s tend to fry themselves?
...or 2010, your search may be over.
:-)
Dean.
reelsmith's axiom: Its going to be used equipment when I sell it, so it may as well be used equipment when I buy it.
Why dismiss power amps? I can build a passive preamp (zero gain). Not thinking. I have an extra tube phono amp.
A passive volume setup may not work, due to low power amp I/P impedance. You really have to be prepared for the 10 KOhm IHF "standard". However, a "unity" gain buffered volume control will do quite nicely. Buffering makes a 100 KOhm volume pot. feasible in combination with a low I/P impedance power amp.
A cheapy 25.2 VCT "Rat Shack" power trafo, 4X 1 A./50 PIV Schottky diodes, 2X 'lytics of decent size, a 7812, and a 7912 make a bipolar PSU suitable for JFET source followers in the buffer role. The only cap. in the signal path is an O/P coupler.
Eli D.
Eli,
I think that's good advice. I have had several instances where a buffer was needed, and they all worked out very well.
In my cases I used a bi-polar transistor and a single ended power supply. All the installations were in a powered chassis and were used to lower the output impedance of the preamp, so power was available. Comparing buffered Vs un-buffered, I could not hear any difference unless the preamp was driving a low impedance load. Several receivers and integrated amps that featured pre-out and main-in jacks had quite high preamp output impedances and wouldn't drive an amp, EQ, or crossover with low input impedance without sounding bad.
Jerry
Eli & Jerry- what about a vintage power amp such as the Sony TA-3200F that has 1.5 volt input for maximum output & 75K input impedance. My CD player & tuber are over a volt output.
The standard output for CD players is 2 volts; but the output impedance varies a lot. My Rotel CD player has a 75 ohm output impedance. 75k is a decent input impedance and you could use a 10k pot in between and not load down the output and have only a 12% drop across the pot with that player. On the other hand, I had a couple of Sony CD players that had output impedances around 1100 ohms. They would still work with a 10k pot; but the drop across the player's output impedance and the pot could be as much as 25%. That's still enough to drive the amp to full output, as it would take a 25% drop from 2 volts down to 1.5 volts to drive the amp.
More later, I have to go.
Jerry
I'm surprised by that Sony CDP's 1100 Ω O/P impedance. Under 1 KOhm is what's appropriate into the IHF "standard" load that all commercial products are supposed to be capable of driving. Perhaps the slogan should be: Sony, a lot of baloney. ;> ) The company has gone downhill, since Morita died. :> (
It is possible to do a JFET buffer with a unipolar PSU, but caps. in both the I/P and O/P circuitry are needed. With their capability for self bias, JFETs, depletion mode MOSFETs, and tubes can have DC coupling on the I/P side of a voltage follower setup, if a bipolar PSU is used.
FWIW. I would use a buffered volume control in combination with a Sony TA-3200F power amp. I believe strongly in adhering to the 1:10 impedance rule. A 10 KOhm passive setup would work, provided VERY low capacitance cabling (as in extremely short, braided, and unshielded) is used between the control and the power amp. Why handcuff yourself?
Eli D.
Eli,
With the buffer in an existing active preamp, there is already an output cap for the preamp, so all the buffer needs is one additional cap for the output.
The two Sony CD platers were an ES model and one of the regular line. Both were measured at 1100 ohms at 1 kHz.
Both were also sensitive to the capacitance of the interconnects, so I used 12" interconnects made from low capacitance coax. Capacitance was in the 25-30 pF range. With typical 3' interconnects with a capacitance of 100 pF, they both developed a hard, bright edge. My old, and dear departed Onkyo DX230 CD player and my Rotel RCD971 don't seem to care about cable capacitance; but the earlier Rotel RCD955AX does. With short, low capacitance cables the RCD971 and 955AX sound identical; but use 3' long, 100 pF cables with the 955AX and the difference is quite noticeable.
I have no idea what the root cause is; but my friend, the analog circuit guru, thinks it might be oscillations in the output circuit caused by the extra capacitance.
Jerry
IF a DC blocking cap. is present at the O/P of the driving unit, an I/P cap. is unnecessary. However, an awful lot of stuff has an opamp and no cap. at the O/Ps. A BJT buffer with a unipolar PSU can't work with 1 of those cap.-less opamp O/Ps, even though a DC offset is not present.
The reason some units get into trouble with "high" capacitance cables, even though they have respectably low O/P impedances, is that they lack O/P current capability. An ability to charge and discharge the cable capacitance is absolutely necessary. Even driving line level interconnect cables requires a measure of cojones.
Eli D.
Eli,
Thanks for that tip about current capability in regard to cable capacitance.
I know enough to check for an output coupling cap, when using a single ended buffer. Plus, I have run into some other stuff when adding buffers. Stuff like muting circuits which work by shorting the output to ground. In my Onkyo TX870 receiver's preamp they put a 2500 ohm resistor in series to limit current from the linear IC at the output, so it could stand the muting circuits downstream of it. The power amp is nicely done; but the preamp is sort of a dog's breakfast of circuit elements. Don't even get me started on the CD input circuit - my rant on that atrocity could last past midnight.
Jerry
Just less electronics in the way- likely a moot point. I have a ceramic Centralab CV-9000 series 7 amp button contact selector switch. I could place the switch solder lugs 1/2 inch from RCA jacks & two 10K pots right next to the switch with one for each channel. The center of switch would seperate left channel from right or I am saying a symetrical layout.
When I sold audio in the 80's I thought very highly of the Denon integrated amps. They are smooth, image very well, are very reliable and have great phono sections with good MC headamps.
Dave
Any model numbers?
I don't remember the model numbers. Thy all were fairly similar. They all had the prefix PMA. The bigger amps had more features but the smaller amps sounded very good on efficient speakers.
Dave
.
do a search in uk or germany ebay or other
look for tandberg,revox,dpa,denesen,audiolab,musical fidelity A1(i love this amp to death)
there are also early arcam and cyrus
hope this helps
I looked at the A1 when it came out, but I never took the plunge. It is a very nice amp. The Tandberg an Revox were very nice too.
Dave
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