[jc9394]

 
Quote:

Not well at all........you should let me take it off your hands.  

Will let know once I got it, was thinking getting a Rega but looks like vintage table match better with vintage receiver.
 
 

 

[RexAeterna]

got my Yamaha R-9 receiver back yesterday, since it had to get repaired. had all outputs,diodes,ect even front panel wiring was re-done. Bias and dc offset set back to factory spec. Tech told me the amp section is similar to the M-80 power amp on how it's designed he use to have and worked on. i noticed noise floor is much better and dead quiet even with my k601's off the headphone jack but due to the power this thing has i have no volume control whatsoever without the -20 muting switch. even with my 600ohm sextetts i have to use -20 db muting switch. i hooked up my sextetts though after some time to the speaker outputs via 4-pin XLR to bare wire and sounds great. background dead quiet, more then enough volume headroom even if i have to have the -20db muting switch at all times.

Tech measured the distortion on it and everything else and says it's really low and fantastic that there is no need to run it in class A, so i haven't ran it in class A yet but will test it later on my speakers since the benefits of using class A is mainly to draw more current at once since all transistors are switched on even at idle. last time i had it before i went to get it repaired i found class A only useful for driving speakers under 4ohms. at 2ohm loads it ran cool as ice in class A but anything higher then 4ohms even when pushing the speakers it'll run hot cause in Class A it's not using up the given extra current and dissipating it as heat. there is no thermal runaway when driving lower then 4ohms nominal on it from experience.

 

[5aces]

Well Im thinking foam it up and put it in one box, then foam up that box and into the second box.

Nothing worse than vintage gear damaged simply by poor packaging.Using these techniques should bulletproof your stereo eqipment:







1) Double walled box
2) Line box with egg carton foam(or thick straight foam) leaving 4" between walls of box
3) Thick straight foam on bottom of box
4) Wrap item in painters plastic or bubble wrap if really heavy(foam can mar a surface with fine scuffs)
5) Place foam padding around item in box to make it tight
6) Cover top with foam
7) Use good quality packing tape with a tape dispenser.Tapes seams first,top and bottom (blue arrows).Overlap each seam with tape on each side to triple seal the seams.(red arrows)
8) Mark box with TOP and FRAGILE stickers/lettering

Don't let your pieces go on the Packing Wall of Shame.
ref.cdkands/packing1

 

[WarriorAnt]

Quote:

Nothing worse than vintage gear damaged simply by poor packaging.Using these techniques should bulletproof your stereo eqipment:



1) Double walled box
2) Line box with egg carton foam(or thick straight foam) leaving 4" between walls of box
3) Thick straight foam on bottom of box
4) Wrap item in painters plastic or bubble wrap if really heavy(foam can mar a surface with fine scuffs)
5) Place foam padding around item in box to make it tight
6) Cover top with foam
7) Use good quality packing tape with a tape dispenser.Tapes seams first,top and bottom (blue arrows).Overlap each seam with tape on each side to triple seal the seams.(red arrows)
8) Mark box with TOP and FRAGILE stickers/lettering
Don't let your pieces go on the Packing Wall of Shame.
ref.cdkands/packing1

A thousand thanks for the photos and the effort!   I'm going out now to hunt for all the materials.  
 
 

 

[5aces]

Moving companies and mattress manufacturers(foam cuttoffs) will have all you need.
Overseas freight forwarders have the crate building skills/materials/information for large speaker/amplifier shipments.
That photo with the U-Haul electronic boxes was the uber heavy Yamaha C-1 & B-1,shipped all the way from Winnipeg,Manitoba to Brampton,Ontario via FedEx.
Lots of bubble wrap,both directions and taped up before being placed inside the foam packing ensured a safe ride.
He also used foam peanuts to fill in any voids left after using the straight foam to pack it tight!
All those switches on the C-1 preamplifier make it look like jet airplane and yet not one them was broken in transit.

 

[Chris J]

Quote:

 
 
Anyone using these vintage receivers primarily with low impedance headphones (Denons, Grados, ATH's) and are preferring them to dedicated headphone amplifiers? 
 
Edit: I wonder if impedance resistance adaptors will help.  

Hi there,
An impedance adaptor will not do what you are looking for: turn a high output impedance into a low output impedance.
If you are an electronic handyman you can open the receiver and replace the headphone jack resistors with a lower value.................like say 5 ohms.
 
BTW,
Any love out there for the Yamaha CR-2020?
My mother has my old CR-2020 but doesn't use it anymore..................hmmm, maybe I should borrow it and give it a try?
 
 

 

[RexAeterna]

Hi there,
An impedance adaptor will not do what you are looking for: turn a high output impedance into a low output impedance.
If you are an electronic handyman you can open the receiver and replace the headphone jack resistors with a lower value.................like say 5 ohms.

BTW,
Any love out there for the Yamaha CR-2020?
My mother has my old CR-2020 but doesn't use it anymore..................hmmm, maybe I should borrow it and give it a try?

 

these receivers will work with low impedance headphones pretty well since they're all discrete units. no op-amps or tubes. the power transformer will help match the impedance of the given input impedance by decreasing the voltages across the resistors to match the voltage needed by the headphone. i just find using high sensitive earbuds/iems is not recommended really.

i heard lot about CR series of yamaha and is highly praised receivers. thing is CR series did not have Class A power amp sections like their integrated brothers. they were strictly class A/B but i did believe their bigger CR series had low impedance speaker driving capability as well if that matters to you. that's why all yamaha famous speakers and studio monitors were at least 4ohms nominal to run specifically off their amps. only class A yamaha receiver is the 1985 flagship R-9 since it used the MX-XX power amp section and can drive up to 30w into 8ohms in class A with zero distortion. has no issues driving 2ohm loads so if running planer speakers or electrostatic speakers with lower then 4ohm nominal they did very well driving them without getting hot and blowing up like other amps. you should defiantly try getting it back and hook her up with another receiver. she shouldn't care as long she has sound.

 

[Chris J]

Quote:

these receivers will work with low impedance headphones pretty well since they're all discrete units. no op-amps or tubes. the power transformer will help match the impedance of the given input impedance by decreasing the voltages across the resistors to match the voltage needed by the headphone. i just find using high sensitive earbuds/iems is not recommended really.
i heard lot about CR series of yamaha and is highly praised receivers. thing is CR series did not have Class A power amp sections like their integrated brothers. they were strictly class A/B but i did believe their bigger CR series had low impedance speaker driving capability as well if that matters to you. that's why all yamaha famous speakers and studio monitors were at least 4ohms nominal to run specifically off their amps. only class A yamaha receiver is the 1985 flagship R-9 since it used the MX-XX power amp section and can drive up to 30w into 8ohms in class A with zero distortion. has no issues driving 2ohm loads so if running planer speakers or electrostatic speakers with lower then 4ohm nominal they did very well driving them without getting hot and blowing up like other amps. you should defiantly try getting it back and hook her up with another receiver. she shouldn't care as long she has sound.

Hi,
The power transformer is for the power supply.
It has nothing to do with matching the impedance of the headphones to the headphone jack.
It's a high impedance headphone jack, the only way to get around it is to change the resistors in the headphone output.
 
I seem to remember that the CR-2020 had a nice relaxing, full sound, but it was not very dynamic?
I don't remember the amp having very tight bass either?
I remember the headphone jack had no trouble driving a pair of 2,000 Sennheisers my brother used to use back in the early 80's.
I also remember it had a nice sounding tuner section?
To be honest I haven't heard it cranked out at any reasonable volume in maybe 10-15 years and I haven't plugged headphones in it for maybe 20 years.
 
Man, that R-9 sounds like a very nice piece!
 

 

[RexAeterna]

i know it's the power supply. it mainly use to block RFI as well. power transformers do help match impedances but depends how the amp is designed. mostly tubes rely on transformers for matching impedances. some solid state uses it for matching impedances as well that's why they have dual layering/windings on some. if your worried about then make a 4-pole TRS jack to speaker output box and run it off the speaker outputs or rewire the headphone with 4-core wiring and 4-pin XLR?

i don't know how the yamaha CR series were voiced like but i think yamaha fellowed the natural sound approach to them like their other amps so it should have no sound signature to itself. most amps shouldn't. must of been the speakers used and the room they were in that will give the biggest impression of sound.

 

[RexAeterna]

Man, that R-9 sounds like a very nice piece!

i just saw this. thanks! it is one yamaha's most under-appreciated amps. people that actually owned one(went for 900 bucks in 1985) liked it more than the CR series. wouldn't surprise me though since the MX-XX power amps are highly sought after power amps still and can still score them cheaper than pioneer or marantz and even sansui offerings. i liked yamaha stuff cause they're the only ones to drive 2ohm loads without blowing up or melting wires inside lol. that's what the MX-XX power amps were known for as well is their low-impedance speaker driving. lot used them for electrostatics and sub-woofer driving cause they can handle low impedances for long periods of time without stressing. i think the only upgrade from the R-9 would be the MX-1000 amp and CX-1000 pre-amp.

 

[WarriorAnt]

I know this is the vintage receiver thread but here is a vintage amp question.   Anyone have experience with  Dynaco MK III amps?

 

[livewire]

No, but I want to. Maybe. I think....
Always been curious, specially about the hot rodded ones.

 

[Coq de Combat]

Hi,
 
I hope this is the correct thread for my question.
 
My father bought this little integrated stereo amplifier in the 80's; AKAI AM-U11.
 
I don't really know much about this amplifier, however, when I put my headphones to it, it sounds ******* great except for this crackling noise that is connected to the potentiometer for volume and balance (it's on the same place). It takes a little wiggling to make it stop crackle, but when it does it blows every other receiver/amplifier I have in this house - especially for headphones. My question is, since I love old vintage amps, should I maybe start looking for old Marantz or Sansui stuff instead and throw this in the garbage, or would it be worth it to fix this one up? I know it sounds great, but the crackling and popping annoys me and if I could find a cheap old amp in good condition maybe it wouldn't be worth fixing this one up.
 
What do you guys think? Does anyone know anything about this particular one? Is it worth fixing it or are there better amps out there for less money than it would take to fix this one up?

 

[Chris J]

Quote:

i know it's the power supply. it mainly use to block RFI as well. power transformers do help match impedances but depends how the amp is designed. mostly tubes rely on transformers for matching impedances. some solid state uses it for matching impedances as well that's why they have dual layering/windings on some. if your worried about then make a 4-pole TRS jack to speaker output box and run it off the speaker outputs or rewire the headphone with 4-core wiring and 4-pin XLR?
i don't know how the yamaha CR series were voiced like but i think yamaha fellowed the natural sound approach to them like their other amps so it should have no sound signature to itself. most amps shouldn't. must of been the speakers used and the room they were in that will give the biggest impression of sound.

You have power supply transformers mixed up with power amplifier output transformers. Yes, I agree, vacuum tube power amps normally have output transformers to optimize power delivery to 4, 8 and 16 ohm loads.
 
Hmmmmmmmmmmmmm.............Maybe I'll try creating a 4 pole can jack for the CR-2020s speaker output.
 
The CR-2020 has a very large power supply transformer but has no power amplifier output transformers. 
I think that's what you guys like about the vintage receivers:  the huge power supplies and is why modern receivers weigh nothing

and why vintage receivers have such solid bass. That's just my opinion.....................
 

 

[BmWr75]

Quote:

I don't really know much about this amplifier, however, when I put my headphones to it, it sounds ******* great except for this crackling noise that is connected to the potentiometer for volume and balance (it's on the same place). It takes a little wiggling to make it stop crackle, but when it does it blows every other receiver/amplifier I have in this house - especially for headphones. 

The cracking noise is easy to fix with Caig's Deoxit.  Read this thread on AK to learn how it is used.
 
http://www.audiokarma.org/forums/showthread.php?t=207005