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ASL Tulip amp mods [message #10659] Sat, 07 August 2004 06:44 Go to next message
spkrman57
Messages: 522
Registered: May 2009
Illuminati (1st Degree)
Just wondering if anyone has a Tulip amp that has been modded, and what the mods were. Also, what kind of output tranny's are used in this amp, would a ouput tranny upgrade be worth the cost?
Regards, Ron

Re: ASL Tulip amp mods [message #10660 is a reply to message #10659] Sat, 07 August 2004 21:45 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
They wind their own trannies. I almost bought one and did some checking.

Re: ASL Tulip amp mods [message #10661 is a reply to message #10660] Sun, 08 August 2004 07:16 Go to previous messageGo to next message
spkrman57
Messages: 522
Registered: May 2009
Illuminati (1st Degree)
Thanks for the info, have you heard if the quaility of the handwound tranny's is very good or not. I plan to run a 3 way Edgarhorn system with this and think I should be able to improve on this amp.

Any other info you can share with me would be appreciated.


Thanks, Ron

Re: ASL Tulip amp mods [message #10662 is a reply to message #10661] Sun, 08 August 2004 08:45 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Well Ron I personally have not heard the amp and it's hard to make recommendations w/o hearing. The Audio club here had a guy who liked it but he only heard it stock. Remmember that the Tulip is input transformer coupled. I guess to increase gain since they put out 3.5 watts from just a driver stage and the output stage. From the little that I know input trans must have a very high step-up ratio to load a single tube; however that requires high turns ratio which could compromise high end response.
The mods I have heard of include:
VH Audio V-cat Teflon coupling Caps
Riken Carbon Film grid-stopper resistors
Sonicap Power Supply filter cap by-passes
IXYS Ultra-fast soft recovery diodes in the power supply.
This should help I hope; the unit is supposed to sound real sweet with these mods.J.R.

Re: ASL Tulip amp mods [message #10663 is a reply to message #10662] Sun, 08 August 2004 12:16 Go to previous messageGo to next message
spkrman57
Messages: 522
Registered: May 2009
Illuminati (1st Degree)
Thanks for the info. I am running EH 2A3 Gold drid 2A3's(RCA 2A3's for serious listening), Sylvania 12Ax7A's(green label), and a Mullard 5AR4 rectifier.

I tried a Blue Circle 21.1 preamp to go with it, but the sound was not very good at all. The same preamp with my MC-240 was okay. So I am wondering about useful preamps with this amp. I had a friend come over with a Bottlehead Foreplay which played very nice. Just hard to match up a preamp with, could that be transformer coupled problem?

I have had this for approx a year, the sound is good once you roll some "old stock" tubes to replace the chinese tubes which tend to be forward and lack the subtle details that vintage tubes have. I know a friend with a S45 Moth amp that shows the difference in quality though.

Thanks, Ron

Re: ASL Tulip amp mods [message #10664 is a reply to message #10663] Sun, 08 August 2004 13:50 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
Absolutely; the source impedance will have an effect on the load. I have only a rudimentary understanding of this subject. The amp needs a particular load impedance so that the source is better controlled by the electrical damping provided by the load. Like a speaker. Flatter response/ cleaner output, and better resonance control will all be affected by impedance matching of source and load.

Some use a look-up factor of 200 or more as a guide. Hopefully some of the brains will see this post and chime in, Eric and Wayne.

Input impedance of the Tulip is 100k so you would probably want 500ohm output impedance on your pre-amp. My AES is 560ohm output impedance. If you were close by I would run it by, but if not try and borrow one. It's a nice sounding unit and it would probably work for you.

That Tulip I believe can run 45's as is; no?

You know as an aside; there will always be something better. Like the Moth; since it sells for 4times the price of the Tulip, it better be. Hope this helps; J.R.

Re: ASL Tulip amp mods [message #10665 is a reply to message #10664] Sun, 08 August 2004 14:17 Go to previous messageGo to next message
spkrman57
Messages: 522
Registered: May 2009
Illuminati (1st Degree)
Funny thing about the Blue Circle preamp is the 130 ohm output impedance, you would think it could drive anything.
Thanks, Ron

Re: ASL Tulip amp mods [message #10666 is a reply to message #10665] Sun, 08 August 2004 15:32 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
So you have a good impedance match; must be something else. Back EMF? Maybe they just don't get along.J.R.

Re: ASL Tulip amp mods [message #10667 is a reply to message #10666] Sun, 08 August 2004 19:40 Go to previous message
spkrman57
Messages: 522
Registered: May 2009
Illuminati (1st Degree)
I don't know how it will work, but I swapped for some $$$ and trade for Audible Illusions L1 preamp. Don't think it will be much different, but can sell off if I don't like it.

So far, the Bottlehead Foreplay preamp plays well with it, Bill Epstein came down and we tried it, sounded wonderful.

I will try the L1 soon, but busy schedule for next couple of days with domestic stuff I have to do, will report findings when I do.

Cheers, Ron

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