[grig]

Are the wooden cups available as spare parts?

third party cups ?.... yes

 

[CJG888]

But not from Foster themselves?

 

[grig]

But not from Foster themselves?

as far as i know, no. But try to send them (Fostex) an email and pretend that you have T60RP that needs a new set of cups for whatever reason..

 

[Dipper Mouth]

Just want to let people who are thinking to buy T60, the rattling/buzzing problem is a huge bummer if you like bassy songs. I had to replace both drivers due to this problem and now one is again buzzing. I demanded a refund after 8 months. Will see if I am lucky enough The bass was also not fulfilling for my taste

 

[Albert Fifties]

T
I Listened to the T50 today, ordered a T60RP. Totally convincing: best harmonics, great voice. No false bass, no muddy mids like the competition, its music. [I've had the Koss electrostats in the past, probably like the 'planar' sound field.]

So the question is: what transformer to use? I have a preamp with a SE driver, using the R120 triode (like using an KT66 in triode mode to give you the idea) with an plate resistance of 700 ohms to 1000 @ 15mA.

• So for instance I need a 7K (sort of) to 32 ohm.
• Alternative a 3k5 to 5K to 16 ohm output transformer, and just hook up the phones to that. Will reflect as 10K or a little higher.
• Which alternatives? Any wild suggestons?

albert

 

[ninetylol]

T
[I've had the Koss electrostats in the past, probably like the 'planar' sound field.]

Why do you want to change from the Koss Electrostats? Imo they have a similir sound signature but the Koss 950/95X are still superior to the Fostex.

 

[Albert Fifties]

Agree but they were broke (leaky diaphragm, I mean I repaired them a few times, ear pads were turning uncomfy, sorry but threw them in the bin.)

I found two transformers by the way:

1. a small E14 based small EI-14 Audio Output Transformer 3.5K:32 ohm (50% nickel probably) that allows 0,2 watt on the Bay for 30 $ / pair
2. a large one of 5 watts that is true single end, 5K5 amorphous iron core single-ended output transformer 32 ohm headphone output transformer on Aliex for $ 50 / pair.

What would be a recommodation? I use modest levels, << 90 dB generally in the room (have tinitus anyway ). The T60RP sheet gives 92 dB/watt, how does that equate to on-ear?

At 1 watt @ 50 ohms (or is it actually 32 ohm?) The abacus says I need some 7 volt for a 1 watt = 92 dB level. On the primary it is then 70 volt or more. go figure what that means. The E14 can't handle the level for sure.

 

[kintsaki]

T
I Listened to the T50 today, ordered a T60RP. Totally convincing: best harmonics, great voice. No false bass, no muddy mids like the competition, its music. [I've had the Koss electrostats in the past, probably like the 'planar' sound field.]

So the question is: what transformer to use? I have a preamp with a SE driver, using the R120 triode (like using an KT66 in triode mode to give you the idea) with an plate resistance of 700 ohms to 1000 @ 15mA.

• So for instance I need a 7K (sort of) to 32 ohm.
• Alternative a 3k5 to 5K to 16 ohm output transformer, and just hook up the phones to that. Will reflect as 10K or a little higher.
• Which alternatives? Any wild suggestons?

albert

It is not clear to me what it is that you are trying to accomplish.
Are you trying to come up with a good amp to drive them?

 

[Albert Fifties]

In fact, yes, I'm trying to drive the phones directly from the preamp, and like to use the preamp output tube as the amplifier tube (my R120 is a triode almost like a 2A3 but with a special heater). But of course that output is line level to start with. Max 1 volt RMS. That level needs some 6-10x extra amplification.

• My main amp is 300B; could I connect the phones to that output?

Sorry to bother you , it looks I make it more complicated than needed (In the past I connected my Koss to the speaker output which was OK with the integrated 8ohm matching transformers). And on my Yamaha, there is a simple phone output . . also connected to the output of the outputstage if I understanbd correctly.

 

[CJG888]

You can connect them directly to the speaker taps, but you would be well advised to use a resistor network and ensure separate ground paths for each channel.

 

[Albert Fifties]

Thanks CJG, I found RobRobinette's pages.
"The HiFiMAN HE-6 is known as one of the most difficult to drive headphones on the market. It's rated at a low 50 ohms impedance but a paltry 83.5 dB/mW and 96 dB/V sensitivity. With most speaker amplifiers the HE-6 would need no attenuation at all. In this case you could simply delete Resistor2 from the resistor network. A 10 ohm 10 watt Resistor3 would supply the amp with 7.6 ohms of Effective Speaker Load to keep it happy." and . . the RT60 has even lower sensitivity @ 92 . .

So I can use the option of using a 10 ohm parallel resistor (no series) to get the resistance down, to 8.3 ohm which is perfectly OK for my 300B SE.
If needed, I can also hook up my solid state 'Le Monstre' where I would probably need a divider, will experiment with the sensitivity there.

 

[CJG888]

In theory, yes. Only the T60RP is much more efficient than the HE-6. You may find you have very little usable range on your volume control (and possible channel balance issues at the bottom of the range). You may be OK, though, if it is a single 300B per channel (i.e. not PSE). Then you will only be putting out about 8 Wpc into 8 ohms.

 

[Albert Fifties]

Thanks, good to hear it is a better efficiency. I've got single 300B (self built and designed, goes from 8 Hz to 45 kHz, LL2572 @4k6) and it gives 5 watts before distorting. Normal volume is already at 9 o'clock here, if you understand.

 

[kintsaki]

Thanks, good to hear it is a better efficiency. I've got single 300B (self built and designed, goes from 8 Hz to 45 kHz, LL2572 @4k6) and it gives 5 watts before distorting. Normal volume is already at 9 o'clock here, if you understand.

The T60 is rated at 3 Watts RMS into 50 ohms. Zack of ZMF assured me it can safely handle 10 Watts RMS.
I have been driving all my T50RP moded phones (T60, ZMF Blackwood SE, Argon, Mayflower, T20RP)
and my He-6, HFM Edition X V2,Ether C Flow 1.1, and Verum One directly of the speaker terminals of KT88 85 Watts RMS into 8 OHms, Crown XTI-2 at 275 W at 8 OHMs, ifi Micro DSD and Massdrop 789 Balanced. Never had a failure. Could run from whisper low to ear spliting levels, no problem whatsoever. 789 Balanced with T60 Argon or Blackwood SE blew away all my other Orthos including Audezes (which I sold). Balanced is the way to drive Orthos.

 

[Albert Fifties]

That is reassuring .
I will do that as well, abstain from buying a transformer, and try to hear the difference of the added resistor (is 'a bit' important in SE - but a higher plate load only ensures a lower harmonics so is not inherently bad .