Jfet BOZ - Page 105

AndrewT · 24th August 2011, 03:54 PM

That result of better sound by fitting a pre-amp tells me that the source was incapable of driving the load you attached to it.

It is the Source you should be trying to sort out.

timbarnes · 12th September 2011, 01:29 AM

Having just finished my F4, I've been thinking about a suitable gain stage for it, and I have built two.

The first was a simple 5534 op-amp preamp: it seemed to work fine, but I wanted to try something a bit more exotic, so I found the JFET BOZ.

A quick lash-up on a matrix board, stuck in an L-shaped support, powered by a couple of 9 volt batteries.

Sounding good.

No tuning yet: I'm planning to try 27V to see if there's much of a difference when I get a chance.

The gain stage is connected to an old First Sound passive preamp, so I have too many cables, but it seems to work. I omitted the gain control from the JFET BOZ therefore.

tim

ramallo · 12th September 2011, 01:49 AM

Quote:

Originally Posted by timbarnes

Having just finished my F4, I've been thinking about a suitable gain stage for it, and I have built two.

The first was a simple 5534 op-amp preamp: it seemed to work fine, but I wanted to try something a bit more exotic, so I found the JFET BOZ.

A quick lash-up on a matrix board, stuck in an L-shaped support, powered by a couple of 9 volt batteries.

Sounding good.

No tuning yet: I'm planning to try 27V to see if there's much of a difference when I get a chance.

The gain stage is connected to an old First Sound passive preamp, so I have too many cables, but it seems to work. I omitted the gain control from the JFET BOZ therefore.

tim

You can try with a distortion analyzer for get the adequate voltage supply for your jets.

Nelson Pass · 12th September 2011, 01:54 AM

Next you will need to try the BA-3.

ramallo · 12th September 2011, 02:03 AM

Quote:

Originally Posted by Nelson Pass

Next you will need to try the BA-3.

timbarnes · 12th September 2011, 02:36 AM

Quote:

Originally Posted by Nelson Pass

Next you will need to try the BA-3.

I'll be at BA looking forward to learning more. Unless you'd like me to get started early...

timbarnes · 12th September 2011, 02:37 AM

Quote:

Originally Posted by ramallo

You can try with a distortion analyzer for get the adequate voltage supply for your jets.

Ain't got one. Just a multimeter. But it is sounding good.

mhouston · 03:21 AM

You'll be happy with BoZ. I've built four, all slightly different and a B1. I felt the B1 had a better mid-range but I needed more gain so BoZ was the answer.

I may have posted this before but here is my BoZ on a cap (BoZoaC). Shortest signal path on the planet.

vdi_nenna · 12th September 2011, 12:55 PM

Quote:

No tuning yet: I'm planning to try 27V to see if there's much of a difference when I get a chance.

Somewhere in this thread, Mr Pass said 16v is the sweet spot. So you are close right now.

Quote:

You can try with a distortion analyzer for get the adequate voltage supply for your jets.

Or, you can try this suggestion.

Source resistor value change was also discussed. I think it changed from 10 to 22 Ohms, but check to be sure.

See post #691
Jfet BOZ

ramallo · 12th September 2011, 01:13 PM

Quote:

Originally Posted by timbarnes

Ain't got one. Just a multimeter. But it is sounding good.

Without a distortion analyzer this post will be a good start point for you

12th September 2011, 01:29 AM	#1042
timbarnes diyAudio Member Join Date: Dec 2004 Location: Los Gatos	Feeding my new F4 Having just finished my F4, I've been thinking about a suitable gain stage for it, and I have built two. The first was a simple 5534 op-amp preamp: it seemed to work fine, but I wanted to try something a bit more exotic, so I found the JFET BOZ. A quick lash-up on a matrix board, stuck in an L-shaped support, powered by a couple of 9 volt batteries. Sounding good. No tuning yet: I'm planning to try 27V to see if there's much of a difference when I get a chance. The gain stage is connected to an old First Sound passive preamp, so I have too many cables, but it seems to work. I omitted the gain control from the JFET BOZ therefore. tim __________________ Townshend Rock III w/ DC motor, EAR 834P, Naim CD5i, Voyage MPD, ODAC, Audio Research LS3, MiniDSP, Pass F4, Parham Pi Sevens 5532 Preamp, JBOZ, DIY Silver cables, Open Baffles, DIY subwoofer, First Sound Passive, Pass BA-3, GainClone, o2 Headphone Amp

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24th August 2011, 03:54 PM	#1041
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	That result of better sound by fitting a pre-amp tells me that the source was incapable of driving the load you attached to it. It is the Source you should be trying to sort out.

12th September 2011, 01:54 AM	#1044
Nelson Pass The one and only Join Date: Mar 2001	Next you will need to try the BA-3.