Forte' audio model two preamplifier

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Forte model 40, model 2 Fet 10HL

I am looking at the schematic for the model 40 and the fet 10HL and thinking there are many similarities. (to my untrained eye anyway!) Does anyone know enough to comment on how similar they might be (for a poor man's alternative to fet 10HL) and how the model 2 might differ technically? People keep mentioning replacing op-amps in these things but are they involved simply as servo amps or as signal amplifying devices? I can't see op-amps in the line stage of the 40. Kind regards, Trevor from Australia. (p.s. thank you Mr Pass for all your designs and shared ideas. I am a big fan of the Fet 10 HL too even if I can only listen to a friend's right now!) I built a B1 for my own home and embarking on an f5 now.
 
I only have the schematic of it's successor, the 40, however I think it's
about the same.

For each channel I see 4 phono loading switches - 150 pF, 1K, 100, and 47
ohms. The default with all of them off is 47K ohm.

:cool:
Mr Pass, I wonder if you could possibly post the Forte 40 schematic you mentioned here? Or (if it isn't handy) might you tell me if it uses the same kind of line stage as the fet 9 and 10 (original non-e versions) I have the *phono* schematic for the forte 40 and the *line* stages for fet nine and ten (old versions) and they all seem very similar to my inexpert eyes. (I think one of them has a diode ccs for the fet pair vs transistor for the others and one has paralleled 2n5566's vs one - I'm not sure why. I have a fet nine myself and am considering a model 40 (as it's balanced by the looks and I'd like to try those inputs on something else). Is the line stage for the 40 along the same lines? Thank you and kind regards, from Australia. 8) p.s. I have read many of your discussions (thank you) and built a B1 too for kicks. I think it's wonderful so thank you for that gift too!
 
Forte Model 2 DIP switch settings

I have the Model 2. The Switch settings:
Switches 1-3 set gain
1 on = 40dB
2 on = 50dB
3 on = 60dB
Switches 4,5,6 set loading
All three off = 47KOhms
4 on = 100 Ohms
5 on = 47 Ohms
6 on = 22 Ohms
Switches 7, 8 set capacitance
Switches off = 100pF
Switch 7 on = 200pF
Switch 8 on = 300pF
Both on = 400pF
 
Official Court Jester
Joined 2003
Paid Member

Attachments

  • FORTE-40-SCHEM.jpg
    FORTE-40-SCHEM.jpg
    119 KB · Views: 1,169
Thank you Nelson! In fact I just pulled the trigger on a Manley Shrimp preamp (low output impedance and 11db gain) to go with my soon-to-arrive Firstwatt F7!! (Mark just shipped it, very exciting). Will try my DIY B-1 buffer first but will probably need additional gain hence the active preamp (driving 88db Gallo speakers, not sure of the outcome yet but dying to try).
 
Hello Audio Enthusiast's

I am in need of some assistance regarding a Forte Audio 40 preamplifier with phono.

I have the opportunity to acquire this item, however the gentleman that has it, lost the power supply in his last move..

Does any one out there have a power supply schematic or a power supply unit available for purchase..

Thanks
 
The one and only
Joined 2001
Paid Member
I don't have something out of the box for you, but you are simply looking
at a decent linear regulated +/- 18V.

I think the store has some raw supply boards, there are numerous
transformer companies like Antek, and lots of regulators posted around.

Perhaps someone here can point you to a complete kit or solution you can
purchase.
 
Member
Joined 2000
Paid Member
Here's as power supply that works well and is very reasonability priced.
I have used both the single and dual supplies from parts-express.com.

It uses LM317/337, so it's no slouch, but not the last word in voltage regs either.
I think you can even use a transformer directly into the reg, without the need for a bridge rectifier. You might want to use a 15v-0-15v transformer. 18v will work well too.

https://www.parts-express.com/adjus...v-to-37v-dc-output-lm317-lm337-desig--320-616
 
Last edited:
Hummmm on Forte model 2 phono entry

Hi everybody,

I buy a Forte model 2 preampli and I like it. I expect I have a small problem. All entry are "quiet" without any noise or "hum" and have a total silence. Unfortunately when I my use my turntable I have a low level "hum" noise only when the needle touch the vinyl. Otherwise, when the tonearm is up, no "hum". Somebody can help me please? Thanks.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.